I'm an 18 year old guy and I can't get it up or keep it up. It started maybe six months ago. I've had five experiences with two different girls where I have been naked on top of them and I haven't been able to get it up. A few weeks ago I stopped getting hard when I masturbated. I have no idea what is going on and I don't want to go to the doctor for obvious reasons. I will eventually if I have to, but I really don't want to talk to my parents about this. Thanks for any help.