My Upside Down backwards infidelity (PART 1)

So to start this story off some context is needed. 7 months ago I moved away to school being forced to leave my girlfriend of 6 months behind but remaining committed to each other. a month in she came to visit me and admitted that she had cheated on me with one of my best friends and his girlfriend. Naturally I was devastated but after a lot of deliberating I decided that I was willing to try again being that we had our own sexual history with this couple. Over the course of the next month and a half it came out that she had lied and had actually hooked up with my best friend two other times including once just before I left. She claimed it was because she had a history of messed up choices and bad relationships and it was her only way to feel close to me while so far away. I went through a heavy depression and did a lot of shit I wasn’t proud of, disowned a lot of friends who had become included in the lies, breaking a lot of things and cutting. I looked for every opportunity to cheat on my girlfriend to level the playing field and feel better to hopefully help me move forward with her but it was difficult while attending third year university.