Hi Song ~
I had what you are talking about ~ my jaw locked for a few weeks ~ i had to have surgery to free it up ~ wasnt a bad surgery and when i woke up i could move my jaw - was so great to get relief!! i could give you details about it but since our bodies are all different what happened to me might not be what happened to you .
Might want to start with a Dentist so that he can get a panograph film off your entire mouth - it shows the jaw joints in this film. Then he could give you the best advise.
i can tell you when i was locked up like that i lost 15 pounds! a diet of soup and slim fast for nutrients
i really feel for you - been there done that.(right at Christmas last year) Hope you get to a Dentist soon - to get you out of pain and eating again. Good luck to you!