What Causes Penis Foreskin Pain And Non Retraction In Erection?

sir,plz help me out of this problem..in normal state there is no problem with my penis but wen it gets up..,the skin over my penis is not going back.in normal state i pull my skin back then it is very easy to get penis out.but when it is getting tight it is very much paining,in this stage there is no pain when the skin is covered and if i pull it back to bring my penis out there is lot of pain i cant overcome that pain plz help me out...