My first was chlamydia. Shortly before I acquired it, I gave a world premiere of a stage play that was a total disaster. It killed my self-esteem, and I was morose for weeks after. I had only a few gay friends, and they were mostly scene queens who let me hang around with them but never really interacted with me unless necessary. One of them was this scrawny black dude named Chris. He followed me into a bathroom one night at a bar and watched me take a piss while he looked over the wall of the bathroom stall. He HAD to have my dick. Since the play's failure, a little positive attention made me go starry-eyed, and I let him suck my dick right there. He asked me to go home with him to fuck him. So I did. I wore a condom when I fucked him, but he was NOT cleaned out and I found shit all over my dick. We washed in the shower, and then he offered to resume sucking my dick with hot water in his mouth. I let him do this, and it felt pretty good.
Ten days later, I had this unbearable itching on my dick. It wouldn't fucking stop. I was practically clawing at it to make it stop, and I tried all remedies I could think of: Gold Bond Anti-Itch Powder was among them. I finally went to a doctor, and told her what happened. Not having a lot of money for such things, I told her that I couldn't make a repeat visit if something were found, so she took my urine sample, and sent me home with Bactrim. And after a couple weeks, it was gone.
I later saw Chris at the poof bar, and told him to get tested. I didn't accuse him, lest I be wrong, but he told me he didn't have chlamydia. He's POZ. He didn't tell me THAT when we hooked up. "Undetectable" wasn't a term at the time, so I freaked out. I knew right then it was him who gave it to me - I hadn't been sleeping with anyone else in months - and I demanded that he pay for my treatment. In my mind, that would have been the honourable thing to do. I had no money of my own, and I suffered because he didn't communicate, and I felt he targeted me. Fortunately, because of my income level at the time, the clinic cleared my bill, and I paid nothing for it.
I've got two other stories for when I got gono, but I won't bore you with the details of those.