question: hi doctor, i am 25 years old and i faced a problem today that my penis does get hard when i masturbate ( I have been masturbating since 15 years old once each 2 days) . Also, i dont have sex often, its just once every month. last 2 months i had a girl friend and i found out that some times while we having sex my penis dies!!should i stopp masturbating? and does the past 10 years of masturbating going to affect my sexual life? and why do my penis dies while im having sex?