Fracture is caused in the bones. penis is musculature not amenable to fracture. As you have tarteted particulars space for more emphasis, probably is has gone numb. You may be okay after some time. Feeling weaker suddenly may be one time affair which may be caused by randomly loosing interest in masturbation. Sometimes you get side tracked while doing sexual activity. Such incidents are normal.
Leave your "partner in crime" alone for a few days. Do a self exam in the shower and feel for anything unusual or pain. If your good with these maybe giver a nice easy wank and take a test drive. Your young, I'm sure your fine. Best of luck.
And one thing I forgot to add.
The pain which I felt was at the place where I used to stimulate my penis more. It was at top left of penis head. And this the place where I felt that breaking feeling. When I get erections now I feel that only that part is having a bit trouble.!! Is it a major thing or it will be cured naturally after some time??