Falsely accused

my girlfriend is convinced that i slept with someone else when we was on a break 3 months ago and now were back together shes breaking up with me because of it. even though i didnt theres no telling her. what can i do..?

I would let her know that you care about her and you would never cheat on her. If she doesn't give you any chance to talk with her, you can text, email, or get a friend to say it for you. Ask her if she has a good reason to believe that you would do something like that. Why is it so easy for her to believe that you cheated? Let her know you are disappointed because you thought your relationship with her was stronger than this. You could also say that if she does break up with you, it won't change how you feel about her and it won't change the truth. You can tell her that if you were the type of guy who cheats, then you would want her to break up with you because you wouldn't deserve her. But you did not and you never would. Additionally, you definitely would not like it if she cheated, so why would you cheat? If she can't give you the benefit of the doubt, maybe you two do need to break up.

I just thought of this as well. If you are unable to talk with her, you can make a video of yourself and send it to her telling her how you feel (if resources and time permit). Consider this along with my other suggestions.