You didn't cheat by any stretch of the imagination. Your bf or whatever he is since he did make it clear he wanted to break up - is manipulative. I can't say for sure what he was thinking initially by his so called break up with you, but from his behavior, it seems to me like it was him trying to manipulate you from the very beginning. If he told you all of those things initially, you had no reason to think that he was still considering you his gf! The fact he denied it later and then begged you to not break up with him using suicide and crap on you - clearly he's not only manipulative, but wishy washy at best, not knowing what he wants.

Do NOT stay because of his threats of self harm and suicide alone. If there is anything to be redeemed with the relationship, ok maybe but at best you need a break from him for a bit. Let him get his head straight first and then go from there. That is only if you want to remain in the relationship. Not just to keep him from hurting himself. Thing is, even if you did stay for that reason, he will have just learned that that behavior works in getting you to stay and I guarantee it won't be the last time he pulls that on you.

I hope this helps. *hugs*