How do I overcome this?

A few years ago when I was 16, this guy was 20 and we were at a party and he was really interested in me. He kissed me and told me he wanted to make out and have sex with me. He was obviously experienced and I he was my first kiss. In the moment I didn’t want to have sex or make out because it was the first time meeting him and i didn’t feel comfortable. But I did like him. Later I went home that night and could not sleep. He just made me so uncomfortable and disgusted with myself. I have no clue why. Ever since that moment I have felt so uncomfortable with guys. I have tried to date but the thought of a guy kissing me or taking me to bed still makes me feel uncomfortable. And he could be the nicest guy possible. It’s only 3 years later that I have finally figured out why every guy I date freaks me out and makes me uncomfortable. It’s really not the guy, it’s the one guy who ruined everything years ago. I don’t know how but that one encounter I had with that one guy years ago has shaped my brain into thinking all guys are better. I don’t know if it’s trauma or what but I don’t know how to overcome this. I want a boyfriend I just can’t get passed the first date because I know what comes later on. If you have any tips or anything you could share that could help it would be greatly appreciated. Also thank you for reading all this.