Well. This post got me fired up. I'm ready to show up to your unit and open up a can of whoop-@$$ -- what you are describing is despicable and I do not know how such a Lord of the Flies culture has been allowed to ferment in your institution. That said,......
Everyone has given you great advice. Make record/report this stuff. You MUST talk to your management.
As for the mean girls,... Look people in the eye and force them to deal with you directly, right there, on the spot -- call them on their behavior on the spot, not a second later. Your attitude should be one that it is clear you expect the utmost professionalism and teamwork from them. When a patient goes south, you make it clear you expect them to do their jobs, as you do yours.
This is going to sound strange and stupid, but learn how to strut. I don't mean really 'strut', but pay attention to your posture. Back straight, shoulders relaxed, head high, and don't forget the eye contact. None of this should be necessary, but until you figure out how to go forward in this situation -- whether that means changing units or staying, or whatever, you need to put an end to this nonsense. Like I tell my kids, "never, ever start a fight, but you'd better be ready to finish one".