<human>: Summarize the given text in a few sentences.

Got together in high school junior year. Basically she cheated on me when we went off to college within 2 months of her leaving. I really wanted our relationship to work out so tried to make it work. Little did I know she cheated on me a three months after the first time. Yes, I know I should've broke it off from there but like I said, I really wanted us to work out. Through all this I've been dealing with trust issues and have brought them up to her. She would turn this against me and make me feel like shit a few minutes afterwards. 

I broke up with her three months ago after the third and final time of her cheating. I'm a fool. However, I'm still having trouble regaining independence. I'm in school and concentration on work has been an issue. My grades have dropped since the breakup. On top of that, she's officially in a relationship with the guy she cheated on me with. 

I asked her for the honest truth and she said she didn't cheat on me while we were together. I don't believe it. I'm no fool. When you've been with somebody for three 1/2 years, you know each others tendencies. 

Sorry for for the rant, I just wanted to give background info on the status of the relationship. Anyways, How do I get past this and regain independence. 

Sidenote: The guy who she cheated with and I were acquaintance. I would always go to his shop to buy milk tea for said ex.
<bot>: ex-gf cheated on me three times. Still feelings of hurt/depression/grievance three months after the break up. Needs tips on how to regain independence.