Erase him from your system. He wasn't worth your time!! He is not even worth the smallest space among your thoughts.
Everybody, let me tell you...EVERYBODY and especially women have gone through this. You are so NOT alone on this one.
Focus on yourself, improve yourself the way you chose to (e.g. work out) and build up your confidence. You know....he might just did you a favor by leaving your life. Who wants a snake like that in their house?

Good luck.