Ii1n i can't forget my ex even though he left me for his ex-wife?

I met this guy at work in May. I had just been there a month. He approached me and wanted to know if I had a boyfriend or looking for one...I didn't take him seriously but I thought he was cute. However, I found out threw the grapevine that he was married and had two kids...THAT WAS A NO NO! A group of us from work went out for drinks and he was there and before the night ended it was just the two of us. We talked and he said that he was going to tell me eventually and that he was legally separated and that it was in the courts. Fast forward a few months we fell for each other I guess. He was unlike anyone I had ever been into. He had tattoos all over his arms..I'm more educated and make more money but there was something about and he was nice and he treated me well. He said his divorced was finally finalized in October. Fast forward to November, I had been going through a rough my mother went into renal failure. So i guess in a way I pushed him away...I would insult him and say things. The week of Thanksgiving he just stops calling or texting. He doesn't respond to my calls anymore...this went on for three weeks. Finally he called and said we never had a relationship it was just a friendship and I wasn't there for him. He said he didn't have time for a relationship but he wanted to remain friends...Then a week later we were talking and I asked was he seeing someone else...he said yes and I found out from a mutual friend of ours that he went back to his ex-wife/baby mama.

She found out through Instagram when he started posting pictures of them together. I was heart-broken and to make matters worse everyone at work is soo nosy. They come up to me and ask oh how do you feel now that he's quit you?!?! SERIOUSLY!!! To be honest I kinda hate him and I've never hated anyone before. And I'm so thankful I didn't sleep with him...another thing is I'm a virgin.

I want to forget this dude so bad!! but it's easier said than done?? So what should I do?!?!