I miss him, he doesn't :(?

Ok so i was with this guy for a year and some change. Everything was perfect. He made so many promises. Everytime we argued he did whatever he could just to make me happy. He was the sweatest boy ever! Everything about him was absolutely amazing. Since we got together mostly every single day we hung out eather i was at his house or he was at mine. We talked every single day. 24/7, and it was not really that he got tired of me because he was always the one to call/text me and also to hang out. One day i found out he had cheated with this one girl. I broke up with him and he begged and begged for me to forgive him but i couldn't put up with it because i just didn't want to get hurt again. After some time that we were broken i found out he was with this girl. That tore me apart. I was devastated. What hurted me the most was the fact that i was still crying over him and he's with her and probably doesn't even remember me anymore. It's been a while now and he's happy from what i've heard. He talks to alot of girls and I'm still single. I can't even talk to any other guy because it just seems like they don't compare. They're just not the same. I can't do this. It's already been 5 months and i still have those moments where i remember something and start crying. I miss him so much. I don't know what to do, and I just want to move on. What should i do?