I can't get over this guy, its been a long time now.?

I can't get over this guy i once liked who also liked me.. We hung out, made out, snuggled, etc. But then we just stopped talking. We hung out once and from then on we havent really talked.. :( Everytime i see him i feel a sense of sadness but there's no going back.. He's moved on. I can't. We never even dated.. I just fell for him so hard. Yesterday, i walked by him in the hall and this girl pulled him over and said "Hey, we need to hang out this weekend." It made me feel like I wanted to just start bawling.. How do i get over this boy? I've even had a boyfriend since him.. But, I can't get over him.