What Causes Numbness In Penis After Sitting Continuously For Some Time?

Hi I have an L5 S1 Disc Prolapse condition that happened 2 years ago. I have problems getting an erection still and I think it's getting worse. My penis gets numb sometimes after long periods of sitting and my left leg gets pins & needles when I sit on the toilet. My right foot is about 30% numb on the outer edge and my right ankle and right buttock cheek have shooting pain at random times. What the hell is going on Doc. what's the story with my penis? is this normal for my condition. thanks from Choko boy.