My 9 month old male pit bull is always jumping up and barking and playing but today when I went to feed him he just sat there shaking and would not eat nothing not even our pork chops... Im worried to death can somebody answer my question?

Well, lets get some more info,
Is he vaccinated?
Neutered?
Do you always feed him human food? Does he eat bones? Cooked or raw? And what type?
Has he been de wormed and flea treated? When was his last visit to the vet? What did they say?

If your dog isn't interested in any type of food then that is a huge red flag. You need to get him into a vet ASAP. There could be something going on internally.