A loss of power that noticable may also indicate the onset of diabetes. This is one that I know for certain is true, being diabetic and all. I found out when I was 16, and thought I was going to be the next Peter North, if you know what I mean, until it just stopped. It was like I kinked my dick like a garden hose.
If all other things are equal (number of times you punch the clown, water intake, diet) then it really wouldn’t hurt to check it out. The best way to tell if you have diabetes is that you will start urinating all the time, like every 30 minutes. Also, if you are always tired a half hour to an hour after meals.
I would look to PE as the culprit initially, but go to the doctor for a checkup if you’re worried.