I had pain in my jaw too and could not open my mouth to eat more than 1/2 inch. The dentist opened my mouth too wide . This problem went away after 3 days. Next time the dentist did not open my mouth so wide. I have a very small mouth so the average person may be able to handle their jaws to be opened very wide. Next time make sure you tell your dentist not to open it so wide.
I think your jaw will get better in time. I would suggest taking Advil due to inflammation.
Hope this helps.
not normal. if this is all your dentist can do i would get another opinion.
It sounds like you have trismus which is sometimes caused by the injection. I would take some tongue blades, use as many as you can that will fit comfortably between your teeth and add one or two a day to see if you can break the adhesions in the muscles that is causing the trismus.