Has anyone felt like this?

I had unprotected sex for the 1st with a guy I know but we not close at all. I've gone to the dr for all the tests and been on meds but in my mind I've contracted something and not sure if I'm creating symptoms cause I'm over thinking everything. Been getting anxiety attacks. I'm so paranoid, I can't get over this. I feel like I'm going crazy and feel so stupid for doing this and feeling like this. Has anyone ever felt like this?