from your symptoms it sounds like the problem is referred pain from trigger points (painful nodules) in the masseter muscle that is at the back of your jaw bone. If you were to press in on your cheek here (from bottom of jaw bone to top in from of ear) you would likely find some very tender spots. With pressure applied they may recreate the pain you feel. The reason it is worse after eating is because of using the jaw muscles. Massage, direct pressure, moist heat and stretching that muscle could be very helpful. Trigger points in the jaw muscles often mimic tooth problems as that is where the referred pain is felt