>she didnt go to bed with anyone yet

How can you be sure? You only need 5 minutes alone with someone to have sex.

You can forgive and forget. That is honorable to do that. But just move on. I know its hard, the longer you have been with her, the harder it is. But you have to move on. If she is going to throw you away so easily she is not worth your time. Move on and find someone who will treasure every second of your company.