I cheated on my ex and she found out and broke up with me.
Have you told anyone else about this?
No, I was too embarrassed to discuss it with anyone.
I know you are probably hurt that your girlfriend broke up with you, but it was warranted. If you are too embarrassed to talk with her, I think it is okay to start to move on. Talking might just open new wounds and hurt you both further.
I'm saying that I can't move on until I talk to her.
You should talk to her then. It could be a way to start to move on is getting that closure that you need.