It's Complicated

So. I was with a guy for many years. We met around high school. One day out of the blue I learn that he wants to end it. He met a girl a few months back and wanted to explore a relationship together.

Well the first 3 months were obviously devastating. But after a while I began to recover. I became a better person. I lost weight. I gained many friends. I was more successful in all my achievements. I even started talking to a guy who was above and beyond what my ex was, is, and ever will be. However that person did not want a relationship and it was strictly unattached sex. Which was ok with me. Anyway.

Then I start getting calls and text from the ex saying he misses me and he regrets everything. To make it worse he was STILL with his new girlfriend and refused to break up with her. I was thinking "Well then what the F* does he want with me?!" Anyway I played along providing support when in reality I was very happy with this news. Then she finally left him.

Thats when he came to me asking for a relationship again. Stupidly I agreed. Well turns out I meet another guy shortly after. And yes I cheated on my ex/bf with this man. Neither know about the other. IN my mind I consider it payback for what he did to me. And this new person is wonderful. I just dont know what to do. I dont need the same drama. But im too scared to end it with either.