<human>: We've been broken up for a while now. Our relationship was long distance for a bit and it started to turn bad mostly because a male friend of hers would make me really insecure as they would spend all their time with each other. After our break up, we decided to stay friends. The break up seemed to affect her a lot more than me initially. She seemed conflicted, would try to reach out to me every now and then, and generally seemed to be in more emotional distress. 

Recently, she told me that she and this same friend have feelings for each other and will probably date. Shortly afterwards, a mutual friend told me that she slept with him before we broke up and continued to do so. This shouldn't bother me because it's been so long, but it does and I don't know how to stop it. I feel sad, angry, and betrayed all at once. 

I've heard the common advice of

1) distract yourself
2) surround yourself with friends
3) time will make it better
...etc, but none seem to help for now.

Provide a brief overview of the text.
<bot>: Found out ex cheated on me while we were dating. Removed her from my life entirely, but it won't stop bothering me.