Hi I Am 25 I Am Sexually Active But Have

Hi I am 25 I am sexually active but have been with same partner for 4 years. She was recently tested and has nothing. I went to the doctors and they 1st thought it was some sort of friction but when he mentioned it could be herpes it rocked me and now I can't stop panicking or thinking about it. It was a small to medium size blister and only had an itch if sweaty or rubbed against. I also sometimes get inflamed foreskin and hurts to pull skin back. Any information would make me feel a lot better. Hoping it's not the worst.