Nightmare situation.

I need some advice from you managerial types. I am currently in a job at which I am almost constantly getting in trouble. I get written up for things that others have been told "you owe me a beer for that one". The running joke among my peers is " we can do what we want 'cause you're going to get in trouble for it" (they're kidding of course...incidentally they have also decided that along with everything else I am responsible for the war in Iraq). Everyone believes I am being targeted by our clinical coordinator but I have up until now vehemently disagreed with that theory. I have also refrained from saying anything bad about this particular manager to anybody. Being the braniac that I am I can see the handwriting on the wall and am actively seeking new employment. 2 weeks ago I e-mailed my unit director (brand new and not turning out to be great) to let her know where I stood because in my unit one nurse leaving will cause a huge staffing issue. Under most circumstances this would have been stupid but it really was the right thing to do. At any rate I have been hearing from people that my CC has been telling other staff people that I am leaving (wasn't meant to be common knowledge and really nobody else's business) and how she "can't wait" until I'm gone. This has been done in our office in front of numerous people and her cronies which of course spawns discussions about what a bad nurse I am and how she can't stand me, etc. She has gone so far as to get into my locker to show people that I cleaned it out (coincidental-I just hated the mess). BTW-I did not send her the e-mail I'm sure my unit director told her. I addition she has been telling people that she's "not sure" if I will show up for my shifts which I find somewhat slanderous as it undermines my professionalism. Because of these actions I am beginning to believe that I have, indeed, been targeted. That being said, I need to stop this behavior (the talking about me part) and protect myself at the same time. My question is would it be an overreaction on my part to file a grievance against her. I am not opposed to confronting her but I'm pretty sure she will twist what I say when she runs to the unit director and I will once more be in trouble. We are such a small unit that I can't have a coworker witness our conversation because then they will become a target. I don't think a mediation with HR is necessary...I just want her to quit talking about me and stay out of my locker. I haven't even left yet and she is dancing on my grave. I find her behavior despicable, unprofessional and downright mean. I will not miss working under her. Of course this had caused me no end of stress. I throw up before coming into work and am terrified of actually doing my job because I am under such scrutiny. It has made me doubt myself personally and professionally and I am in an emotional tailspin. I want out of nursing entirely but since that is not possible I am hoping to switch to an ambulatory care type setting. Unfortunately it is taking some time to get through the hiring process and I am really anxious to move on. Thanks for your help guys!