Honestly at this point I think you're better off just breaking off contact. From what it sounds like you've got a thing for her, but she's into guys and not into you, and thus drama ensues. By continuing to hang out with her your feelings won't go away.
This love/hate relationship is also NOT healthy. It sucks to lose friends but you need to worry about your own mental health right now. Start finding some other people to hang out with / talk to, and let her live her own life.
You also seem a bit possessive, especially with that scene at the dance. I think you were out of line there, and maybe you still have this mentality that she's "yours" and nobody else should have her. You need to break that habit if you want to have healthy future relationships.
I think that once you get over her and realize she doesn't 'belong' to you, you can start talking to her again, but I'd be really careful, since old feelings die hard.

Out of curiosity, what exactly was your most recent argument about? That might give some better insight into the situation.