Hey Shannon,
Oh definitly my jaw feels that way when it's fatigued. Just like any other muscle. Be careful when chewing that you don't bite your tongue as I have many times. Try resting it and putting a cool cloth on it for awhile and see if that helps. Don't eat any food that requires a lot of hard chewing like steak. Try softer food until it lets up. Let us know how it's going and good luck at the doctors. Take care and have a nice weekend.
Hugs,
Pat