I was in a relationship with someone recently that did some similar mind-fucking. After a year of being treated like shit and just generally putting up with her, I finally had to break up with her. It was my first serious relationship, so I guess that's why I put it off for so long. All my friend would tell me she was fucking crazy, I never listened. Stupid move. I'd hate for you to make the same mistake, even if the people telling you to not bother with her are strangers on a forum.
I JUST moved to a new city for college, so ending our year-long relationship and then moving somewhere where I knew NO ONE was probably a bad move, but to be honest I couldn't be happier. Here's some things to keep in mind to help you get over the post-relationship trauma.
Firstly, DO NOT stay in touch with her. AT ALL. At least until you've gotten over it. My ex got a new boyfriend before I had moved on completely, it drove me CRAZY, even though I wasn't talking to her. It's not worth being around.
Secondly, DO NOT regret anything. Even if you regret being with her after being treated like shit. DON'T. I don't regret a thing from my last relationship, realizing that made me a lot happier. Not because being/staying with her was the right move, but because it helped me grow as a person, and learn what kinds of things to avoid in a girl, and how not to let them walk all over you. Girls aren't attracted to wusses, so use this experience as a lesson rather than regretting it and learning nothing. Embrace what you've learned, accept that you have to change how you deal with girls, and work with it.
Lastly, friends. I just moved to this new city, and I knew nooobody. It sucked ass. I was lonely for a LONG time, and had nothing to comfort me. The only thing I thought about really was her, I had nothing distracting me. Luckily for you, you're still around home. If you hangout with your friends enough, even meet new people, eventually you'll start to realize there are more important things in life. MUCH more important things. My studies and my new friends have made life AWESOME, I haven't even bothered to seriously look for a new girl yet. I'm livin' the sweet life, and so should you.
Hope you can take this shit seriously. It's hard now. But believe me, NO girl is worth doing anything drastic over. As shitty as you feel now, you'll get better. And you'll meet someone worth being with, since now you know who and what to avoid.