Betrayed by boy

At the end of July I was introduced to a guy who was really into me and we started talking. I am someone who doesn’t participate in hookup culture or anything (nothing wrong with it I personally just know I get attached) but I eventually lost my virginity to him. Right after, he told me he wasn’t in the correct headspace for a relationship and didn’t want to get my hopes up because he has a lot of stuff going on in his life and is feeling depressed and he didn’t want to hurt me. I honestly believed him because he got emotional and he was super sweet at first. Like if he noticed I look sad or anything he would always check on me and stuff like that and tell me how amazing and pretty I am. He was super nice and showed he cared about me after for a while and we did it a couple more times but then he kind of started to get distant after a bit. I honestly feel like he was playing mind games with me to try to keep me around but by doing the bare minimum. We would talk a few times a week but I knew this wasn’t enough for me and almost removed him off everything because I was starting to get sad. I knew I deserved better but I guess I was still holding onto all the good and sweet moments we had together. Then two weeks ago today, he was texting me all night and eventually asked me to come over and I did. Then the whole week after we didn’t talk and he eventually stopped responding to me. I thought that was weird because he hasn’t really done that to me before. Fast forward a few more days and I see a post of him and another girl. I found out he got a girlfriend right after I last slept with him. I feel so betrayed and lied to and having OCD has made me feel worse about this whole thing. All of my friends didn’t like him anyways and they have all been great and have really been there for me and supported me, but I can’t shake this feeling I have. I cried a lot after the initial shock of all of this, and I have been sleeping a lot and can’t really get myself to eat. I constantly feel like I’m going to throw up because of this whole situation and my brain keeps randomly putting the image in my brain of him and the other girl together. This is tough for me because I always knew I deserve better than what he offered me but it still hurts because I feel like he was just telling me what he knew I would want to hear to get me to sleep with him, especially because I told him I don’t do meaningless hookups and he told me multiple times he didn’t see me like that and that I’m not just a hookup to him. Has anyone else been in a situation like this that knows how to stop these thought loops and how to cope? I also feel like I’m going to have a hard time trusting again.