What Causes Unbearable Pain In Jaw, Head And Neck?

I have an unbearable amount of pain in my jaws, head, and neck. This has happened once a year ago, and I was told it was "TMJ" by an urgent care doctor and put on prednisone and pain medicine for a short period of time. It went away in about 3 weeks. Now (i think) its happening again. I've been getting some dental work done recently and asked my dentist about it. She told me to ask my doctor since it has happened before. The pain in my jaw started 5 days after some bridge work, and 2 days after a tooth ache began. I made an appointment with my dentist for the tooth ache and my doctor for the jaw pain. Today (6 days after my jaw pain began) I underwent a root canal for the tooth that was aching. my appointment for my jaw is tomorrow morning. My question is should I cancel that appointment with the doctor? The pain has gotten worse, and my dentist still remains uninterested in the issue. She did however check my bite to see if that was causing the discomfort, and she said it was normal. Am I over reacting by rushing off to the doctor, even just to take a look and see if maybe there's a more simple solution or explanation.. I'm worried that I'm wasting my time and the doctors time, but on the other hand I can't stand another day of this feeling. Any advice would be very helpful, thanks!