Boy drama

So there was this boy that I really liked but I treated him so wrong. When I was drunk at a party that he brought me to I kissed another guy and later on that guy invited me to hang and we kissed again and the first boy found out. The first boy ended things and told me that once I realize what I want to contact him and stuff. Well the boy that I kissed played me and I completely regret everything. I miss the first boy so much and idk should I just leave him alone or should I contact him.