you really should not depend on random ppl without any clue what they're talking about as your sources of information. let me clarify some things... prostate cancer is not cancer of the balls. the prostate is a gland that is just outside the bladder and your urethra (your pee tube) goes right through the center of it. prostate cancer is for you to worry about when you're over 50 and cant pee, because your prostate is blocking the pee from coming out.. not now.
and trust me you do NOT want a prostate massage. it involves sticking your finger in your rectum (thats where your poo comes out of) turning it towards the front and moving it up and down, massaging this soft mass of tissue (your prostate). usually its done to get semen samples out of a man without him having to masturbate.
hope this helps. and dont try so hard to make things better, just enjoy the orgasms you have now.