Pain in genital area. It gets worsen.

When I masturbate after a day somethimg start happen in penis . I do not know is this happen in pennis or penis nerve . it is like. a sudden current pass through penis and I masturbate again like within 2 days after firt masturbation. Problem gets worsen now it feels like my nerves of penis is constricted which I can't tolerate . then after a week or two week it become normal slowly abd slowly.This thing happen only and only when it is not erect . when erect nothing happen but after erection it gets worsen . I already masturbate with the gap of two months now . blood , urine , culture and scrotum ultrasound all are negative . there is nothing. PLZ PLZ HELP ME I M VERY DEPRESSED ABOUT MY FUTURE LIFE. WHUCH IS NEAR TO ME plz plz suggest something