You sound like a kind person who has gotten unintentionally involved with this person due to her lack of boundaries and your need to get along. I understand allowing a co-worker some liberties because it's just you and she stuck together at night, and if you don't work together well, things won't work at all.
You also sound like you've done a bit of amateur psychological analysis of her. But you're a nursing student, not a psychologist or LCSW. Put aside your ideas of what's wrong with her and concentrate on what needs to be done.
The basic problem is she is troubled mentally -- how, we really don't know, and a psych nurse, LCSW, psychologist or psychiatrist are really the only qualified people to judge exactly what is wrong. The only reason you need to know or make an educated guess what her diagnosis is, is in order to extricate yourself. How you react could possibly cause a specific type of reaction on her part.
Based on her behavior, she sounds very needy -- needy of attention (telling people she was hospitalized), and needy of a friend. She also sounds like she has poor boundaries -- there are many professionals with mental illnesses their co-workers would be surprised to learn about because they don't go around telling people they're mentally ill or were hospitalized. (I will leave it for another thread to discuss the ways in which mental illness could be de-stigmatized if such professionals DID surprise their co-workers or others in their personal lives by revealing that they have a mental illness.) She also sounds like a "drama queen" -- a non-professional term but an accurate one. She might be histrionic, as you say, but there are so many other things it could be. I knew a bipolar who was *constantly* starting drama because she lived off it.
First your problem is the way that she has pushed into your life -- and the way that you have allowed it. It sounds like you let it happen initially because you were trying to be kind and you were also very practical: you have to work with her, so maintaining a good working relationship is important, and avoiding friction is also important.
Second, she has accepted the invasion into your personal life as the status quo, and pulling yourself back (or pushing her boundaries back) is going to upset that status quo for her. Your knowledge that re-setting the boundaries more appropriately is healthier for both of you will not change the fact that she will undoubtedly perceive your withdrawal negatively.
Third, you still need to maintain a good professional (if possible) working relationship, in order that both of you can get your work done on the shift where you depend on each other.
So, first of all -- you need to be honest with her. Don't make "You" statements; make "I" statements. You have to tell her how you feel, but without red-flagged words that can distract a dramatic person from the point. The less you make it about her, and the more you make it about you, the better her reaction will probably be.
From what you've said, you sound uncomfortable with the way things are. So tell her that. Say, "Jane [whatever her name is], *I* am very uncomfortable with the way you're always telling me your personal problems and telling me very private things. *I* don't know what to say when you tell me such things, and *I* am not the right person to talk to if you need help. If *I* were in your shoes, I would try to find a counselor or clergy person to talk to -- someone who is qualified to give you advice and make suggestions. *I* might also try a support group, such as Families Anonymous or Emotions Anonymous [or AA or NA or whatever else might be needed in her case]."
You also sound like you're worried. So tell her that. "Jane, *I* am worried that you reveal too much personal information to people here at work. It could have negative consequences for you. *I* am afraid what people will say about you behind your back because people always gossip in work places, that's just the way work is. If *I* were in your position, I would keep many of the things you tell people to myself, because *I* would worry how they would use that information."
You also sound like you feel burdened. So tell her that. "Jane, *I* feel helpless when you tell me all the rough things you're going through, because I know that I can't really help you, but *I* can't un-hear it once I know it. *I* am having a hard time listening to all of this stuff from you because it is upsetting to *me* to have to hear it and know I can't do anything about it or help you. *I* would appreciate your discretion on these matters because *I* feel it's too much information. *I* would appreciate it if you would give me a break."
Believe me, I have been where you are, and I've had to have such difficult conversations. Some people, you can't sympathize with them, because then they will just pour more misery out; you can't advise them, because they have a million "Yes, but" reasons why they can't do what you're advising; and you can't solve their problems for them (unless you can demonstrate that they're a danger to themself and/or others, and have them appropriately committed).
And, I myself suffer from major depression, atypical, so I also understand the perspective of a truly mentally ill person. I have been on medication for 20 years to manage my depression, and I've been able to hold down jobs without informing everyone I work with that I'm 'mentally ill'. A couple decades of meds and a decade or so of counseling has let me get very good now at stepping back from my "feeling state" to a "thinking state" and examining whether my judgment or behavior is rational, and try to modify or adjust my judgment or behavior.
But many (if not most) people with mental illness, especially younger mentally ill people (I'm in my 40s) can't do that very well, because it takes *living* with your disorder and *trying* to function -- and treatment -- to develop these skills. And that can take years. (In my case, it took my 20s.) I can recognize when I'm not thinking straight or when I'm using poor judgment, perhaps because of a situation (recent loss) or a change in state (PMS mood swing). But many mentally ill people can not do that because they simply don't have the experience and/or have not had quality treatment over a long enough period of time to learn how to do this.
And some just aren't motivated. I wanted to graduate from college; I wanted a career; and when that ended (lay-off), I wanted to make a career change (to nursing) and, once again, graduate from school and have a career. I am not the most mentally healthy person in the world, nor probably the most mentally healthy RN, but I am functional and patient care under me never suffers because I am committed to my work. (And also because -- due to recent sickness and loss of my parents and a step-parent -- I have been in patients' or family members' shoes, so I know what it is like for loved ones to be hospitalized, and I try to care for patients and their families the way mine were -- or the way I wish mine had been.)
Some people, however, are too caught up in their own problems to be motivated to try to be functional and productive, and they don't have the years invested in realizing that it is healthier for them to try to be functional and productive; they want the "easy way out" and to not have to try, sometimes because they just want to be lazy, and other times because they truly believe they're incapable. (And, for some seriously mentally ill people, they truly *are* incapable of being functional and productive.) I'm not sure which it is in your CNA co-workers' case, but your statement that she has indicated she would like to use the mental illness to have to work less or work less hard means she may be one of those types of mentally ill people.
The problem for people like your CNA co-worker is that, if you told them they were mentally ill, they probably wouldn't believe it. Obviously she's going around saying she was hospitalized, so she has probably been diagnosed (if that is even true -- the hospitalization).
But it sounds like she has a total lack of self-reflection and no ability to analyze her own behavior. So a lay-person (you) diagnosing her mental illness and telling her what's wrong with her just won't work. If she's trying to shirk work as you think she might be, she will both want a mental illness diagnosis but will also maintain within her own mind the belief that she's not mentally ill, she's just misunderstood, or she's "special" or whatever.
If she was actually hospitalized for a mental illness, I would suspect she has been RXed meds and either never took them or took them for a while and stopped (that's the #1 reason why psych patients wind up in ERs -- they stop taking their meds).
Understand that some mental illnesses (like many chronic illnesses) are hard to treat because the medications have unpleasant side effects and patients tend to become non-adherent. Also, for bipolar and schizophrenic patients -- and some anxiety-panic disordered patients -- being in the mentally ill state (psychosis, for example, or mania) feels "good* physically. They don't need to sleep, they have energy, they think rapidly, their senses are very keen, and their possible hypervigilance feels like a positive quality. (For many, this will all eventually spiral up into being overwhelmed with racing thoughts, inability to focus or concentrate, visual and auditory stimuli, forced speech, inability to complete tasks, unproductive agitation, paranoia and/or delusions, and an otherwise total breakdown in ability to function in the world and with other people -- but the ride up to that peak can take some time.)
Taking appropriate medication (antipsychotics, antianxiety meds, etc.) *dulls* all of those seemingly positive physiological qualities. Personally, I've always thought that if you have to have a mental illness due to heredity and/or environment, depression is the best mental illness to have -- because you WANT TO TAKE YOUR MEDS, because they make you feel *better*: the fog lifts, you have more energy, you can focus and think more clearly.
This is not the case for schizophrenics who take antipsychotics, or bipolars who take antipsychotics, or some anxiety/panic disordered folks who take anti-anxiety meds. Most of those meds slow people down, and some of them have unpleasant side effects like weight gain, muscle tics/tardive dyskinesia, decreased libido, anorgasmia, erectile dysfunction.
Also, for any of these diagnoses (schizophrenia, bipolar, anxiety/panic disorder), it is not uncommon for suspicious, paranoid, or highly anxious thought patterns to make them afraid to take their meds, either because they are delusional and think the meds will allow others to control them (schizophrenia, bipolar) or because they are afraid the meds will dull their thinking/behavior or are harmful and/or have harmful side effects (anxiety/panic). So, yet more reasons why people with these diagnoses are hard to treat and have difficulty adhering to treatment and medication regimens.
The point is, whatever your CNA co-worker's diagnosis is, you don't know. So you don't know if she's getting treated or not. If she was recently discharged, she was probably RXed meds; but if her behavior hasn't changed much, she may not be taking them as directed or at all, for the above-mentioned reasons.
This makes it all the more imperative that your statements be about *you*, not her, to minimize her negativity and potentially hostile reaction (depending what her disorder is, she might think you're "with them" or that you've "turned against her" or that you "just don't get it" or aren't up to "her speed" or whatever).
If you appear to take on the inability to cope -- i.e. the mental/emotional weakness within the dynamic you two have established -- it will inevitably change the dynamic, because she is used to you being the "stable" one, and she is also completely unable to consider the point of view of anyone but herself (what she needs, what she needs to talk about, what is going on in *her* life). By stating your uncomfortableness, your worry, your feelings of being burdened or knowing too much info, you flip it around (we hope) and force her to consider how *her* actions make *you* feel (if not how they affect her).
But remember, this person probably has a limited ability to look at how her own behavior and impaired judgment are affecting her own life. So there is probably nothing you can do *for* her -- and probably all you can do is protect yourself and establish and maintain healthy, firm boundaries.
Stop taking her calls. Don't "cold turkey" on her calls, but start taking only 1 out of every 2 calls. If she asks why you didn't pick up or didn't call her back for the 1 out of 2 you don't take, just say you were "busy", you were "out" or you had a headache or other ailment and were laying down or sleeping.
Then, days or weeks later (depending on how she takes it and how fast you think she can accept your emotional "weakness"), take only 1 out of 3 of her calls. Then only 1 out of 4 of her calls.
And, while at work, throughout this time of taking fewer and fewer of her calls, continue to use "I statements" (I'm uncomfortable, I'm emotionally exhausted, I'm worried, I feel helpless, I can't do anything, etc.) to maintain and firm up your boundaries.
Whenever she starts to go into her usual behaviors and too-intimate revealing of personal information, you need to speak up and use "I statements" to re-iterate that you can't "cope" with her TMI. If she persists, you must get up and do something different -- say you have to go to the bathroom, you're going to the vending machines, you left a patient on a commode, you see a patient call light, whatever -- just reinforce that you can't (and won't) continue to listen to her drama by excusing yourself.
Hope this helps. Remember, while you may have begun to listen and to accept her too-intimate confidences out of kindness and practicality (of needing to get along), it is kinder in the long run to let her know that her behavior is off-putting and socially unpleasant. In therapy with some behaviorally disturbed or autism spectrum disordered kids, sometimes therapists put 'healthy' (or healthiER) kids with the behavioral problem kids, because it is through the social relationships, the healthy kids' maintenance of boundaries and appropriate behavior, and through the modeling of social behavior, that the disturbed kids learn to modify their own behavior. (Assuming they're not too disturbed -- which, if they are, and they're dangerous to other kids, they don't get put with others, anyway.)
You can be that healthy person with appropriate behavior, modeling normal social behavior, and helping her see (probably on an unconscious level) that something with her behavior with others is "not right." Because she is already an adult, she may have a limited ability to learn, but unless she is *really* in a mental health crisis (i.e. psychotic, delusional, in the middle of a panic attack), she will pick up on your overt cues if not your subtle cues. And by using "I statements" and making it about yourself, you kind of force her to consider *others'* feelings, which it sounds like she is too wrapped up in her own dysfunction and drama to do.
She may not survive this transition. From what you've said, she sounds quite overwhelmed. (Did she hospitalize herself, or did someone else hospitalize her?) She may act out. She may wind up hospitalized again.
She may also be crafting a "mental illness/disability" pattern of behavior, so that she can work less and not get fired under ADA rules. (This may be part of why she has openly told some people she was hospitalized for a mental illness). Try not to be contemptuous. Most people who want to work less *do* have some kind of emotional or mental problems.
I mean, we ALL would like to work less and earn more, but healthy people realize that's not the way the world works. Healthy people also realize that we would lose some self-respect, dignity, and/or pride if we did actually get paid or get government assistance to NOT do that which we are perfectly capable of doing. And most healthy people enjoy getting out of the house and being productive. Of course, in the case of nursing, many of us hate the stress involved, so it's a fine line... but it's relatively safe to say that most people in nursing, or who remain in nursing of any kind, get a sense of fulfillment from helping others. And helping others also helps us forget about our own problems and gain some perspective on how 'bad' we think our lives are. (There but for the grace of God/Gaia/Allah/Krishna/The Great Spirit/Buddha go I...)
Go slow, but go as fast as you can. It is better for both of you in the long run. And, being hospitalized is not the end of the world for this woman if it happens again. Sometimes it allows a person to get their disorder under control, because they're not doing it by themselves in their own (unstructured) life -- they are in a supportive environment with structure helping them to self-regulate and stay on their meds. (Of course, this depends heavily on the facility and your insurance... sadly.)
Good luck. You will need it. And, try to learn from this! Remember how this person made you feel initially -- most likely, you had some kind of gut reaction about her oddness or too-quick sharing of intimate info -- and think about that gut instinct you had. Use that gut instinct in the future to be more selective in how personal you get with co-workers. When you get that "funny feeling" about someone, maintain your distance, detachment, and always use "I statements." In general it's best to use "I statements" with ALL people. It clarifies communication and is direct and honest. (Unless, of course, you're lying -- but in this case, you're not lying -- you really are uncomfortable and stressed by this relationship with this CNA co-worker, the things she chooses to share, and the way she frequently contacts you at home.)
Hope this helps.