I guess if it were me, I'd want to know when she was cheating on me? If it was at the beginning of our relationship 2-1/2 years ago I wouldn't be as concerned than if it was at the end of last year or something.

I am a little concerned about your relationship with yourself and being down on yourself instead of angry and upset with her? You have not done anything wrong. I would get some therapy and try to straighten out myself before I would tackle whether I want to try to continue a relationship with her. Are you all living together or just "together" and seeing one another a lot? I would cool the relationship until it is clear what she means by "wants to be with you" in actions, rather than just words. She has to do trustworthy things to gain your trust is how you trust her again; that takes time since she blew it before.