Almost two weeks ago, I engaged in unprotected oral sex and foreplay. A few days later, I noticed this sore on my anus. It itches occasionally, but not too bad and it's not painful, just uncomfortable at times. Nothing has burst or scabbed over. I was wondering if this is herpes, another STD, or just a bacterial and fungal infection. Thank you!
The first two pictures are what it looks like now and the last three are what it looked like before: