Cheek lipoma removed years ago (just above my jaw line). Since the surgery, I have had a lot of pain in my jaw. Why? (Photo)

Since the surgery, my jaw has caused me problems. Talking too much, chewing, yawning, etc. cause my jaw to hurt. Once my jaw starts hurting, I get a really bad headache. I've seen multiple doctors and can't get a diagnosis. However, the doctors I have seen are through the VA, and they havn't done much to try and find the problem. They hear headache, and send me to neurology. Neurology hears jaw pain, and send me to dental. And repeat. I need to know who to go to, and what tests/scans to ask for.