This sounds like a really distressing symptom. The best physician to initially evaluate this type of problem would be a primary care physician
such as a family doctor
or internal medicine doctor. Jaw muscles that are achy or exhausted can be due to a few different problems. Sometimes the temporo-mandibular joint (TMJ) can become sore and inflamed making chewing painful. This is quite common and can be treated by most physicians and even dentists
. Another problem you would want to rule out is Temporal arteritis. This is a disease where the jaw muscle does not get enough blood flow causing pain whenever the muscle is used. It can get so severe that people stop chewing all together. Other symptoms of Temporal arteritis is scalp tenderness, loss of vision in one eye, or pain in the shoulder or hip joints. This is a syndrome that needs to be ruled out because it can cause blindness. I suggest that you schedule an appointment with your primary care physician. Her or she will take a detailed history and perform a thorough physical exam. Likely, if your doctor detects some additional signs such as tenderness over the scalp, or painful joints, then he or she will order some blood work and possibly some imaging. Good luck.