Been having epididymitis for 2 months. not chlamydia and urine cultures come back negative. already took doxycycline, cipro (ciprofloxacin) and zithro. what is it?

Doubt epididymitis: Epididymitis doesn't persist for 2 months. It causes enlargement and tenderness of a single testicle, almost never both; and doesn't cause ongoing testicular pain for this long. So I doubt you have epididymitis. Non-response to those antibiotics is strong evidence you have no infection of any kind. Suspect chronic pelvic pain syndrome (see excellent Wikipedia article). Nothing harmful! Good luck.