Talk to Urologist on Sexual Abnormalities

Discharges (color like water but thick) huge amount of fluid before, while and after of erection. Sometimes it became painful with burning under urine track. I m facing this issues since last 15 years and had a checkup/test for urine track and nothing was wrong. Now I m feeling difficulty in sustaining the erection for long time and premature ejaculation. Request for opinion and consultation.