combatting post-sex guilt ?

I’m 20 and I really don’t have many sexual interactions. Probably because besides during my one relationship, every time I do anything remotely sexual with another person, I end up feeling guilty and anxious afterwards. This happens even though I’m excited/into it before and during the interaction. After, I start to think that the other person has lost respect for me/thinks poorly of me, even though each person has been friendly, totally courteous and respectful through the time I’ve known them.

I’m so upset that I feel so guilty, and I want these interactions to be entirely positive in my mind. I’m all for women being in control of their sexual lives!! Any suggestions for how to keep the good vibes going?