<human>: I'm a 19 year old guy and she's 20. Basically, we were together for 2 years, broke up because of reasons that were mostly my fault. I wasn't spending enough time with her and I was being over-protective. She said she was okay with that, but I felt like I was holding her back and I caused a lot of arguments because of my jealousy. I just felt like it had to end.

In a facebook message, I told her that I was completely over her after we broke up. This was, by the way, a complete lie. I just am not into "on-off" relationships, so I told her this as a way to convince myself that it was, in fact, over. I still had these feelings for her but I had no intentions to act on them. She didn't talk to me for about a week and a half after that. Then I started to change my mind. I had really strong feelings for her again and I wanted to fix things. After lots of advice from friends, I called her and we talked for a long time about everything and decided to give it another shot. Then she said, "If we're gonna do this again, it needs to be an honest relationship..." and went on to describe that one of her ex's (who I always hated) was in town, and that after I told her everything on facebook, she went to his house and they had sex 3 times over two different days. This is all within about a week and a half of us being single. 

I know that I told her I was over her and that she needed to move on, so I don't think I can really blame her for doing what she did. It's just so hard to get over this. I feel like throwing up whenever I think about it but I don't want to tell her. How should I face this, reddit?

Can you give me a shortened version of the text?
<bot>: Broke up with girlfriend, start talking again 2 weeks later, find out she slept with her ex while we were apart, how do I get over that so we can move on?