I [18 F] caught my boyfriend [18 M] cheating and we broke up but I am obsessed with him

This is my first time on Reddit, so please be kind. If we’re young, but anyway. Some background info. I've never had a boyfriend like this, no kissing or anything. We met in sophomore year, and we are total opposites. He's the class clown, and I'm the quietest person in the class. He fell in love at first sight and we started talking. He was the sweetest ever. He asked me out and everything was good except junior year. My mental health started taking a massive toll that I missed school and I didn't tell him about it, and he eventually asked for a break for his mental health, so we broke up for a bit. I didn't know then, but he was drinking behind my back and wouldn't reply for hours, so naturally I thought he wanted the break just to cheat. I became friends with this guy, and he forcefully kissed me. I just froze. I'm not going to say it was an accident because it wasn't. I let it happen and my boyfriend, who i was on a break, saw it, and he wanted me back, but then he tried making me jealous with his ex by flirting with her, but we fixed it and got back together. anyway sorry for the long backstory. Yesterday I found out through one of my friends that he had been texting this girl 21, since June 2025, so literally a year ago. I saw the messages saying that she was gorgeous, and he wanted to wife her up and, in the end, he told her he wanted her and that he didn't have a gf. That destroyed me because my mental health was still bad. I got diagnosed with OCD and BDD. He knows what cheating meant to me. He knew how I'd been cheated on in the past and how my mom almost lost me due to catching my dad cheating and how I had to grow up listening to my parents yelling because he was always cheating. He didn't know how much I loved him. All he told me was that she meant nothing to him, and he was bored and all of that meant nothing and I decided to break things off. Here's the problem. I can't stop thinking of him. He had one chance. He knew my history. He hid it for a year. I feel disgusted. I don't think I can do this but another part of me remembers us. Remembers his eyes. Remembers feeling safe. Remembers the kisses, our pictures, our routines, the way he showed up before. He's all I have. I have no friends and no one to tell this to. I can't imagine living without him. I'm obsessed with him. I wanted it to be him so badly. I miss the life I thought we were building. I had everything planned, our story about us being high school sweethearts, our future kids, the idea of growing old and dying together. Whenever I love someone, I become obsessed, and I gave him everything. I even told him my story about being SA my whole childhood that I haven't told anyone because I thought we would be together. I wonder if I was prettier he wouldn't have done this. I was raised with getting married as a virgin and only being with one person my whole life and I changed that for him. I thought I could have intimacy because we were going to get married. A lot of the time I was uncomfortable, but I wanted him to never leave. I don't think I'll ever be happy again. He was my happiness. I don't know if I can live without him. Am I ever going to move on?