What what you do if this happened to you?

My whole like I never believed in love. I dated this guy for 2 months and I thought I truly loved him. We always fought but only about him not hanging out with me a lot of texting me quickly. I was always afraid he'd cheat on me. One time, I asked if he was cheating on me and he started freaking out. A week later he tells me he wants to break up and I told him to give it awhile it's a bumpy road. The night later, he tells me he cheated on me and kissed another girl. I was sad and he wanted to break up. I found out he had sex with an 8th grader on our two month anniversary instead of just kissing her. I don't know if it's a rumor or not but he probably did. He's dating her now and he's a sophomore. I'm starting to move on. But it still hurts to think about he ****** a girl and didn't want me back and didn't fight for me even thought he told me he always loved me. He always snap chats me and I just ignore them and open them. Last night he sent me a blank one just saying "I'm sorry" like wtf hahaha he's ****** up