Okay so me and my ex boyfriend dated for 10 months and when we dated he did some things he wasn't proud of (getting drunk, cheating on me 3 times and we fought at least once a month) but we were still in love no matter how much stuff we went through. And we didn't talk for 3 months after we broke up, now we're talking again and I don't know what to do cause he keeps trying to get me back, saying he's sorry and he'll do anything to prove I can trust him again, saying that he'll even wait till the end of the world to prove it and give me as much time as ever. I mean I want to believe him but I just don't know what to do anymore.. help?

I wouldn't believe him, I wouldn't even be talking to him. I would tell him to leave me alone. That's what I would do after all he has done.