About a year ago I had a stupid unprotected sexual encounter. Afterwards a few days later, I got a rash and has a string of symptoms. I waited past the window periods and went a got tested. All came up negative 2, 5, and about 10 months. However after having no recent encounters they swabbed and found something, I guess an infection since they prescribed me Amoxcillin, however now I still have some itching and burning around my head and around my anus sometimes, it gets worse at night, and after being screened for every STD in the book, I am thinking it's herpes even though I have never had any sort of outbreak or anything like that besides the string which were treated. I noticed it got better on the antibiotics though and my doc says I shouldn't have anything. Any suggestions to what it might be.?