Dude, whatever it is, it sounds serious... you can't even clench your fist?!?!
Here's a link to the flesh-eating disease symptoms:
http://www.hc-sc.gc.ca/iyh-vsv/disea...h-chair_e.html
The symptoms of flesh-eating disease include a high fever, and a red, severely painful swelling that feels hot and spreads rapidly. The skin may become purplish and then die. There may be extensive tissue destruction. Sometimes the swelling starts at the site of a minor injury, such as a small cut or bruise, but in other cases there is no obvious source of infection.
It sounds VERY contagious, so if I were you, I'd seek a secondary opinion, and stay away from people for now.