For about a month now I have had a stinging or sometimes a burning in the tip of my penis. A lot of the time it looks inflamed. Also sometimes but not all the time it looks slightly like I have goosebumps and or sicoloration. I've been to the doctors for urine tests and blood tests but there weren't any iregularities. I am also not sexually active but do masturbait. Sometimes when I don't masterbait for a while it gets kind of better but I still have symptoms. What's wrong with me?