I noticed a swelling inside the Urethra coming out, like an extra flap of muscle

I'm not entirely sure if this counts as a "Sexually Transmitted" topic as I havnt had sex anything such like in a few months now. But the other week after masturbation I noticed a swelling inside the Urethra coming out, like an extra flap of muscle. I have thus stopped masturbating but in the past few days it has became worse and the tip of the penis seems to have begun to peel. There is no pain at all (minus the odd itch because of the peeling). I have searched and searched and have yet to find an answer and I am begining to become worried as it just all started from what seemed like nothing.