I have the same problem as a few others on this site, but no one has really answered their questions -- except to tell them not to worry or that they are being paranoid -- so I am posting, myself, in hopes of a better response.
I have masturbated my whole life (I am 46), and plenty vigorously at times! I have had sex and played sexually to the point of soreness on multiple occasions. But three weeks ago, after going several hours with a partner (mostly being masturbated by hand, without lube), the skin on my penis got swollen and puffy. The next day, instead of letting it rest, I masturbated myself and of course it got worse. Since that time three weeks ago, I have left my penis alone. The swelling went down in a couple days but in its aftermath, the skin has been loose and wrinkly in a way that I've never seen it before, as though it were permanently stretched out. Erect it looks normal, but flacid, only the head looks normal (I am circumcised, by the way). The skin on the shaft looks like a sharpei dog, full of wrinkles and folds. It's so loose it practically sags down from the underside. Facid, my penis also feels softer and floppier than it did before.
Not to belabor the description, but in case this adds any clues for recognizing my condition: another new thing about my new, 80-year-old-looking penis is that as it goes from limp to erect (I have made this happen a few times, just to make sure things are still working), it gets a strange kink in the middle and looks misshapen. Picture one of those long, hot-dog-shaped balloons, inflated on both ends but with a single band in the middle where it doesn't inflate.
I am not worried I've got a disease or anything seriously threatening my health. I just want my normal penis back. Any advice would be greatly appreciated. Thanks.