How to leave the man you love?

We have a family that he cheated on with some girl and though i tried forgetting and fixing i just cannot! It wont leave my mind so i dont want to be selfish and be with him and constantly remind him of what he did so im planning to move back with my family in another state but i love him still and i know that in the long run if I see him with someone else it will hurt but I rather him find happiness with someone else because if he cheated on me than he wasnt happy. I also want to be happy and move on without hurting for him.