I can’t stop thinking and I need help

I (late 20s M) unfortunately and regretfully lied to the people around me to hookup with a guy I didn’t even know. It was my first experience ever and although I felt confused given nearly 10 years of getting hit on by guys without any real dating life. I’ve always leaned straight/acesexual but my reading materials included same sex stuff as well. My brain won’t stop letting me forget that moment, the internal screaming that I shouldn’t go through with it and even worse during. It was just him blowing me in his car but it was a unfortunately consensual dreadful experience. When it was over I felt completely different, used, disgusted, and couldn’t see myself as me anymore. I knew I didn’t swing that way but I did it. Now I’m swamped with mental anguish over that one regret. Even worse is knowing it’s not for me i almost did it again last night. I’m so glad I had someone stop me because I was honest about it but in reality those thoughts are eating me alive. I’m getting therapy but tonight alongside yesterday have been especially bad. It sounds desperate but I just need to talk to people; speak if anyone has similar history or experiences. Anything is greatly appreciated please.