Irritation tip of the penis after unprotected sex

[Simondid]

I had a one night stand. Drinking the whole night. This girl stayed with me the night and woke up to her on top of me, grinding. I know I had contact penis to her vagina. When she seen me wake up she stopped. I did not ejaculate. Waking up to this was a surprise. The day after no issues. Three days after the incident I notice that the top of my penis started to feel itchy and/or warm. I have no discharge, no warts or other rashes. When I pee there is no pain. I don't have any stomach pain. The irritation at the tip comes and goes. Feel it for a few hours then its gone for a few hours. I am about a week into this situation. I have an appointment to get tested for STD in a few days. Not sure how many guys have felt this. I don't want to try anything on it yet until I know its not an STD. I have crazy anxiety. I am not highly sexually active by choice. The last encounter before this was about a month ago. Being intoxicated made this one night into a nightmare. Any suggestions would help or other questions that I can answer. I do not have any current STD's nor am I able to get anyone pregnant. I had a vasectomy three years ago.