I had an old filling removed on one of my back teeth 2 months ago. There was some decay around the old filling so that was drilled as well and the tooth filled. I had some pain off and on, but the pain wasn't localized to the filled tooth - it radiated over that entire side of my mouth, from the middle to the back, top and bottom, my gums ache and my jaw hurts up into my ear drum. I went back the other day and the dentist ground the tooth down a little more to improve my bite, but the pain now is excruciating - it comes and goes but almost causes me to pass out with the pain. What's going on?