I would like to add my expression of support for you. You certainly got a raw deal! When you're vulnerable, the people around you can be like animals, who seek someone who has a weakness and go in for the kill.
I'm a wannabe psych nurse, and although I've not worked on a unit, I find that I've always tried to apply what I know, in my work. It sounds to me like you were carrying out your roles as wife and nurse, well. That psych nurse had you buffalo'd by offering you consolation and then pouncing. That is a sure sign of "passive aggression". Beware of people who are just too nice!
You have a lawyer, and I hope he/she's earned your trust, as hard as it is to bestow trust on anyone now. I like to find out what experience a lawyer has, when he/she is working for me (I'm divorced from one). Be sure yours is an expert in Labor law, and not a product of a law school that garners little respect (like some night schools, and online "universities"). Unlike doctors, lawyers don't do residencies in a specialty. They join a firm that specializes in the area of law in which they're interested, and almost have an apprenticeship with one of the partners there, for many years before becoming one themselves. So find out if he/she's an associate or partner.
Then slip questions into your next meeting, like, "What happened with another client who had a problem similar to mine? Are you and the judges knowledgeable regarding the atmosphere in hospitals, and conditions under which nurses work?" I just went to a Labor lawyer about age discrimination I've experienced, and he volunteered that he was new in town. I asked him if he'd seen any of the judges here, and he replied that he had not. I suggested that he sit in their court rooms to see their perspectives, and decided not to hire him. Remember that your lawyer is your esteemed employee, and you have the right to find out what his/her game plan for your case is, in regard to how they represent you.
My divorce lawyer decided at the last minute, upon being asked by my husband's attorney if the case could be postponed a month, that he'd do that. He didn't even call me that Friday. I just happened to call his office to see what time I should be in court the following Monday and his secretary told me that my case would be "continued". I said that I didn't want that, and she said, "There's nothing you can do about it".
So I called a friend of mine who is an attorney, and asked her what I should do, as I had a trip planned the following month. She told me to go to court at 8 in the morning Monday, and when all the cases were called, stand and calmly say who I am, and that I was against a continuance, when the other lawyer said the case would be continued. (Since my lawyer hadn't asked for it, he wouldn't be there.) My heart was in my throat, but I did that, and the opposing lawyer hastily said, I'll see her out in the hall, your Honor."
When we were in the hall, I told him that I hadn't known the plan he'd made with my lawyer, and I'd made arrangements to be out of the country by the end of the month. Later I realized that what I'd portrayed that day, was that I was a woman who wouldn't be shoved around! That lawyer toed the mark with me, and everything I said I wanted, was done. My lawyer was as impressed with what I'd done, almost as much as I was.
The reason I'm writing this, is to let you know that it's important to hold your head high, when confronted with the issues they bring up, and give everyone the impression that your conversation with the psych nurse had been private, and she breached confidentiality. Seeing a psychiatrist (I've done that, too) is a sign of strength and willingness to face your "dragons". There is no shame and every reason to be congratulated about it. If you have a toothache, you see a dentist; and when you ache elsewhere, you see a doctor who can help you get better. Unless the medications prescribed for you had a warning label saying that you shouldn't drive, and/or you could be drowsy taking them, it was like any other medication, like an anticholesterol preparation.
Most night nurses experience fatigue at work, and since your obligations toward your husband involved interrupting your sleep, that can be understood, as long as you got at least 6 hours of it. When you have less time to sleep, your mind accommodates that, and longer REM cycles (which provide the most rest) occur earlier than usual, lasting almost all the time you're asleep. Ask your attorney to mention that, and provide him with articles from the internet about it.
Your employer had no right to have you tested for drugs and alcohol; and you were right to go along with that, ever the compliant employee. The results are very much in your favor. I had a bad experience when I worked nights, and tried to get on any other shift. Other nurses didn't want me to be on days, and some wanted to teach the childbirth preparation classes (without proper credentials), that I taught at the facility. They lied about me and before I knew it, I was out the door.
There is very little that can be done regarding "wrongful discharge" if your state has "at will" employment practises. However, you've been maligned and that's something that can be fought. When "character assassination" takes place without cause, it puts employers
who do nothing to correct that, look very bad in court. Ask your attorney if he/she will stipulate that. Having your psychiatrist in court to testify (a letter will not suffice) that there was no reason from a mental health standpoint, to keep you from working the schedule you had, both employers owe you for the time you've lost, due to placing emphasis wrongly without basis in fact that you couldn't work satisfactorily. In this country, we must observe that everyone is innocent until proven guilty!