I have been where You are before. My First Love, My First Girlfriend screwed Me over severely. She decided to cheat on Me with another Guy cause at the time He had a lot more money and basically..She's greedy. After She had done it She realized that She truly loved Me and knew what an awful mistake She had made. She spent the next seven Years trying to get me back and while I would never recommit to Her I, fool that I was, spent the next seven Years cheating on My Various Exes with Her on and off. Until I finally got Married to My Wife and put an end to it once and for all 17 years ago. So don't worry..it, eventually, will end. I had no willpower to resist Her either so don't feel too bad, and I remember missing Her so badly I could not breathe and I also remember wanting to rip My heart out too.
I know how You feel, hang in there..You'll work it out somehow.