No clue whats going on with my urethra

Patient: Hi so i’ve been having this irritation in my urethra after im done urinating. I see no discharge from my penis, however ive had this pain in my right testicle for the longest time. its sensitive to the point then i check the epididymis with my fingers its a very sharp pinch. ive had unprotected sex one with my girlfriend once so i dont know if that has something to do with it. when i urinate it actually is a relief of the irritation. also ejaculating is a relief as well. I wont feel it during the day and the exact pin point is on the frenulum but its inside. I have no clue what this might be but im praying its not a (STI).

Symptoms: Irritation in the urethra after urination