Everytime I have sex with a new guy I lose sleep for days/weeks out of fear for STDs

Even after using condoms and checking for bumps around the crotch, I still manage to lose sleep for days after single sexual encounters. Last time the guy didn't even cum but I managed to freak out for 5 days because a week after the fact I got a rash on my ass on a thursday and couldn't get a doctors appointment till tuesday so she could tell me to maybe start washing my underwear once in a while. I cried for fucking hours completely convinced I had contracted a minor STD like herpes. fast forward to last night I had sex with somebody 10 years older than me and looks kinda skinny and unhealthy...I haven't been able to sleep longer than a half-hour worrying about having contracted HIV even though we had safe sex. now I have to fucking wait for weeks before I can fully feel better about this.Can anybody relate or give me some advice to calm myself down? I try to tell myself "what's done is done" and look up promising statistics citing about a .2% chance in transmission on average in my situation, but still can't manage to stop staying up worrying about HIV, even as the very managable condition it is today