Cheating and lies

My girlfriend and I met 5yres ago at a club…not a great place to meet people but it happens. That night I was extremely sad over my breakup with my ex of 3 years. My girlfriend knew by the end of the night why I wasn’t interested. I was heart broken and really depressed. That same month she called me and we started to talk more. I asked her out knowing that she would be my rebound. That’s where all the drama started. That same month I met another girl that reminded me of my ex. I kissed her once but it wasn’t a major kiss. Anywho, I ended up telling my girlfriend about it becuase I didn’t want any liesin our relationship. I thought everything was fine becuase I told that girl that it was a mistake and that she should work on her realtionship. Well, one day I went up to my current girlfriend apartment and one of her guy “friends” came out of her room with her. She said that she was giving him a massage>>>Well, after that she kissed someone else while out with her friends. In turn what goes around comes around. SHe then kissed the same person again at her friends wedding. A year ago I told her that I cheated on her with a friend of the families. I told her the same week becuase I hate guilt. She then told me that she cheated on me 2 years ago with one of our friends that we hung out with all the time. They both knew about it for two years and kept this from me. She said that she didn’t tell me becuase she didn’t want to lose me. I at keast told her the truth in return I got 2 years of deciept. What should I do??? I left her a week ago becuase I can’t get the images out of my head and my PRIDE is very much hurt. I now we are both at fault but, the trust is completely gone. I’m afraid that everytime she meets a new “friend” something is going to happen.