Masturbation. Of cum, please help. '

My friend quoted 'I'm 19 now. I started masturbating when I was young. However I didn't realize I used to practice prone masturbation until recently. I successfully practiced usual hand masturbation before too, but on a low scale. I felt more comfortable, easy and enjoyment rubbing my penis on my bed. My penis is a but curved to right and backside, I'm worried about some disease I read on net. I recently realized that my penis foreskin didn't completely fall back. When I realized all these things, that is yesterday, I practiced normal hand masturbation and pulled my skin back. It hurt just a bit, but it was okay. I was taking very much longer than usual. When I finally reached the stage, I peed instead of cum, please help.'