Penis irritation? Trimethroprim nausea?

24 year old male. Healthy, physically fit, one sexual partner. No major health problems before.

I have irritated the tip or just inside the end of my penis more so the exit hole of the urethra causing pain inside and an increased frequency in urination. It feels like maybe some bacteria has gotten inside there or just too much friction from sexual intercourse and masturbation. Perhaps a combination of both.

To describe the feeling it feels like something is stuck just before the tip of the penis. And the frequency of peeing has increased to move this out. 7 days before these symptoms, I ejaculated and felt like not all of it came out. Which that night induced a high urinary frequency. It stopped, I refrained from sexual activity for 2 days, then once I engaged again the symptoms arose but 10x worse. This is just the feeling I can describe. It’s been 5 days and each day the urinary frequency increases and is now becoming painful. Stinging at all times of the day. And the urinary incontinence is very uncomfortable, most nights I don’t sleep at all. If I don’t take pain killers I actually can’t sleep at all or do anything.

I went to the doctors and explained my syptoms. I had my kidneys checked and my urine tested immediately, which came back completely fine. As much as I tried to explain the pain as more of a friction problem or an infection, the doctor was more than sure I had bladder/renal issues/UTI.

I was prescribed trimethoprim 200mg for 5 days as a treatment for this issue. It’s the first day of the course of antibiotics and it has made me extremely sick all day. Initially I thought it was mental and I was just having an off day from eating in my usual fitness/bodybuilding lifestyle routine. But the thought of food was making me gag and by the end of the night in intervals I was forcing myself to eat or else I’d feel worse. The nausea is now so extreme I’m convinced it’s an adverse reaction to this drug.

My main concern is that my issue with the penis and urination has no had any relief also but I do not want to confitmue with this medicine, as reading online many people have experienced this extreme nauseated feeling. I’m so close to vommiting the room is spinning whenever I close my eyes. I have not slepted again this is probably the 3-4th night like this. What can I do in this situation? I can’t tske this medicine anymore as this side effect is way too harsh to endure. It has been 15-20 of pure nausea on the verge of vommiting and it’s so uncomfortable.