20M, visited many doctors, but my condition is still undiagnosed.

I've seen multiple urologists over the last 7 years, but I still don't have a diagnosis.

Symptoms:

• Burning pain during and after urination
• Sharp pain during nightfall discharge that lasts until it ends
• Blood after urination
• Foul-smelling urine

Tests/Findings:

• Urinalysis has been repeated countless times and is always normal (no infection).

• I've been evaluated for cystitis and prostatitis—both have been ruled out.

• Cystoscopy reduced my pain by about 70% for one week, but the symptoms returned and became even worse afterward.

• I have never masturbated or had sexual intercourse.

What happened afterward:
When I went back to the urologist who performed the cystoscopy and told him that all my symptoms had returned and were now even worse, he suggested that I must have done something harmful to my private parts. However, I haven't. I honestly don't know what's causing this, and I'm looking for answers because I'm in pain every time I urinate.

My question:
What conditions could cause these symptoms despite repeatedly normal urine tests and no evidence of cystitis or prostatitis? What should I investigate next?