My boyfriend thinks I cheated at a party we went to together, now I was gone talking to a girlfriend of mine and he could'nt find me and asklol of a sudden he left me there and went home, I come home to ask why he left and he said because he knows I cheated. I've been crying for days, I really didn't what do I do?

Ask him what proof he has.

He is either looking for a reason to break up, or feels guilty because he's cheated on you.
Either way, that is not how a real man acts. Dump the loser before you get any more emotionally invested. Do you really want a husband who would leave you at a party? Or throw baseless accusations at you? Noooooo... I think not. Dump him.
He's obviously a very insecure person and if he cared about your well-being he would never
Abandon you at a party. Good luck to you, hope you find a true love who loves & trusts you.

That was reallly immature of him to do. Try talking to him about the situation and see what's happens.