Please give me a good solution for my penis problem. When I am sleeping on bed my penis become harder. If I come down from bed and by standing trying to fuck. I can't" my penis becoming loose. If I again sleep on bed and doing like massage for 30 secs with hand it's become harder But when I standing from bed down. My penis become loose and I am pumping with hand to become harder it's not become harder why like this what's the problem.