Well, last evening I worked as a med nurse (LPN, in my facility), but when necessary during any shift I toilet or dress patients, feed them, supervise baths, do dressing changes or other treatments (LPN duties, usually), pass snacks, brush teeth, clip nails, hand out tissue, or hold hands. In other words, I do it all.
I get the idea of not wanting to work extra in something other than your usual role. It's uncomfortable. But if you're a nurse, CNA duties are within your scope of practice. And you can't be too good to do it. Too tired, though, I get. I've had many days when I'm too tired to haul another patient on and off the toilet--I'll ask one of the aides for help. I'm not Supernurse. But I will participate. I'm not proud--I'm a nurse; pride is pretty much out the window at this point--fart, vomit, drop a BM on the floor, sneeze a wad of snot on my face, it's all good, no problem. Nurse life.
Short-staffing sucks. We are chronically short-staffed. But again, nothing new. I've worked in badly-staffed situations for decades. You get used to it. I walk in to work and automatically go into hyperactive mode; I move fast, I talk fast, I have little time to talk to anybody, including patients; and when you work in psych, that's a problem. But that's modern nursing. I do the best I can. It's all anyone can do.
Nonetheless, don't feel bad that you didn't want to work extra in a role not your own. Feel bad that society values healthcare so little that it won't prioritize nursing--the backbone of modern healthcare--enough to esteem and pay nurses and nurses' aides what they are really worth. That is the real problem.