I'm 28 and I've been masturbating since puberty. I would masturbate atleast twice a day everyday. I would always masturbate the same way. I would lay on my stomach and when I would get erect, I would bend my penis towards my feet and use my hands to rub my penis against my bed. I've used the technique well into my twenties, but now use the conventional method more. When I get erect though my penis curves down and my erection isn't that strong during sex or masturbation. Could this technique that I've been using cause my curve and erection problems? Thank you.