4 Year Relationship Issues?

I had been with my girlfriend for 4 years. I wanted time to myself 3 months ago and didn't know how to explain it to her properly. I handled things wrong and she felt and thought that I didn't want her anymore. Her friends also mentioned to her that I could be cheating. Which wasn't the case, but I was speaking to girls though. I'd chill with my friends more than her but that wasn't actually it my "friends" smoke weed and that's what I was really there for. I was trying to run away from my issues. After a while a guy in her math class started to flirt with her. He told her he likes her. He has a job, and access to a car from his parents. I have no job and access to no transportation but a bus. After about 2 months, she tells me she already made her choice. Shes going to be his girlfriend. I was surprised since we were together for 4 years how could you just move on to someone else that quickly. I react in panic and I give her my passwords and show her that I have nothing to hide. I show her the conversations with all the girls I have spoken to. I had spoken to them in a flirtatious manner after I thought guys were flirting with her and she was flirting back with them. So I showed her everything. Her response was: I knew you cheated. Everyone was right. She cried. I cried. I just want her to know the truth. Everything is a big misunderstanding. She won't believe me though because 3 months passed and and shes with him. Full out relationship. I understand the miss-communication that me and her had and still has. She thought I didn't want her. When it was really because I was frustrated. I felt as if I was living a fake life. My feelings & perception of things were. I didn't make her happy, I got her mad too often, we got into a lot of fights, I didn't take her anywhere nice enough. & the + I felt as if we needed time apart time to ourselves. So I tried to play a game, I tried to make her leave me. It worked. I didn't intend for her to leave forever though, and I handled things wrong and she felt that way. She felt extremely hurt. = ( The one I love... all I want to know is.. is there any chance of us being together again? & if there is! HELP ME!!