Urological pain for months?

Hello! In March, I (M23) had sexual contact with someone (M45) who had ureaplasma. Then with someone else (M39) who also described prostate pain. Both times, I was passive and had unprotected oral and anal sex.

Since those two occasions in March, I've been suffering from burning pain, primarily in my urethra and testicles, but also in my bladder and anal area. It's burning, pulling, and stabbing, and is now slowly becoming unbearable.

I've already been tested for bacteria and STDs several times, as well as twice for semen analysis, and nothing ever came back. I've been prescribed antibiotics several times for suspected ureaplasma and prostatitis, and they didn't help.

However, an antibiotic completely eliminated the symptoms for 2 to 3 days, until they slowly returned. The doctors don't want to prescribe the same thing again.

During a cystoscopy, where a camera is inserted into the urethra, they only found that the urethra was inflamed. Shortly before that, I had a urinary tract infection, which was treated. Since the operation, I've also had severe pain up to my bladder.

It starts mildly in the morning and gets worse after the first urination. After urination/orgasm, it hurts a lot more than usual. My testicles also hurt a lot more after orgasm.

I'm really at a loss. The doctors are labeling me as healthy, and I'm getting desperate. Please give me some advice, because I can't take it anymore.

Thanks!