Are you telling us you masterbate too much? *chuckles*
Repetative rubbing and vigerous sex can cause cysts to appear I think (try googling it). If you're really worried about something, especially with your penis - see a doctor.
i once masturbated and dont know how the whole got collapsed, so when i ejaculated.. well, technically i didnt, because all the sperm got stuck half way up the penis. hurts, a big bump appeared to the left side. something like this: ( ' ) \ '·. ..\ ·' ...\ \ .... strange...
after a few weeks the bumb went off, but i nearly got a panic attack. :/