<human>: Can you summarize the given text in a few sentences?

Preface: I'm a college student.

Complete shit 3 year relationship, accumulates with girlfriend cheating on me for months maybe 5 months (skype, texting, email, meeting up, all very sexual). Second time cheating (probably more, who  knows she's a real cunt). Seems like a few of her friends know, encourage her to keep cheating, real classy people. I can understand maybe someone is stupid enough to be immature and cheat themselves, but how can you be so immature that you encourage it as an outsider. Although I take comfort in knowing the type of people they are.

Back to her, she finally stops cheating and allegedly starts really focusing on the relationship. I finally find out 3 month after it stopped. Confront her, and she completely denies it. Pretty much the Spanish Inquisition ensues and she finally admits it. She is super upset, says the relationship wasn't working while she was cheating. At that time I had my busiest semester (college), needed her there most for support, but she was off cheating behind my back. Anyways I dump her.

We unfortunately signed for a place together, so we are living together this year. She is currently working out of town, but comes down every weekend and we hang out. Still have sex, and basically act like a couple. Most times I can stand it, but I get real fucking bitter often.

Always just refer to her as my friend when other people ask, but she quickly juts in and says girlfriend. Don't see a real future with her, but at the same time real upset that I don't. I really wanted something, I mean really really, but I just think it has gone too far.
<bot>: Blindsided, wanted something but now it's seriously ruined. Can't bring myself to leave it or want it again, been 3 months.