From last couple of weeks, whenever i engage in sexual intercourse with my partner, after inserting my penis inside her vagina, due to friction my inner skin of penis starts bleeding, maybe due to tiny cut that gets created on it; Initially i thought it'll be only for once or twice, but now its happening every time i have sex n therefore i am not able to penetrate n have proper sex with my partner as it gives me tremendous pain in penis. Please help me what to do??