Help please

So I lost my virginity like a week ago in a strange situation and that person and I just haven’t talked since (promise I’m not a whore I’m just 18) welllllll I can’t get it out of my head. A huge part of me wants to find a good guy and just let him do as he pleases but another part of me is so worried and stressed about to possibly of getting pregnant that I have literally scared myself out of having sex again. I can’t take the pill or most other birth control options due to the fact of my heart condition and the medication I am already on. I know how to be safe I just overthink everything.