You need to get him to the vet ASAP. If his jaw is locked, he looks as though he's swallowing his tongue he's in trouble and you should get him to the vet, if it's after hours then they must have an emergency clinic or a vet on call that you can talk to. You don't say how old your dog is but please get him medical help this does not sound like something minor it sounds like something going on in his brain.
