Since the first time of my sex, my penis head feels very sensitive. I do have a history of 15 plus years of masterbation. I won't ejaculate instead, handle my penis rough particularly the head area. I have good erection but while plan to penetrate my heart rate goes up and will ejaculate right after inserting. Sometimes, my erection will be gone before penetration. But while watching porn i have good erection. Help me to reduce the sensitive of my penis head.