<human>: We started dating when we were 15. The three of us were very good friends and we would spend a lot of time together. Little did I know she liked him more than she liked me, despite being my SO.

I don't know how long she was cheating on me for, but I found out last year when he got drunk and told me she would often perform oral sex on him.

When I confronted her, she said it was true and told me that she didn't love me and that I couldn't satisfy her.

I broke up with her, and a day later they had gotten together.

I felt like my heart was being crushed. I stopped talking to both of them. I thought I loved her and she loved me back. 

I want to get into a new relationship but I'm scared I'll be hurt again. I know it probably won't happen, but it's like an irrational fear in the back of my mind.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: Got chested on by my girlfriend with my best friend. Now I'm irrationally worried it'll happen again.