lower abdomen pain associated with bladder and burning urination

I am 27 years old men.
RFT . Urine test. Usg - Normal

Continuous lower abdomen pain associated with bladder in pelvic region below navel and burning urination. Pain worse after urination and penis burning all time. Doctor recommended only painkiller and I can’t take it as I have gastritis. Help me .

Doctor told it might me prostatitis or cystitis but not diagnosed.