You need to promptly take yourself to a Board Certified Oral and Maxillofacial Surgeon who treats TMJ disorders. There are many possible causes for your condition (bone, muscle, tendons, ligaments, infections, cysts, tumors, etc...). The longer a patient has been experiencing symptoms without appropriate care, the worse the condition may become and the more difficult it is to treat.
Expect that the surgeon with take a complete history, perform an examination and take radiographs. After this, they should have a good idea where the physical problem is coming from and recommend treatment.
Information contained within this reply is intended solely for general educational purposes and is not intended nor implied to be a medical diagnosis or treatment recommendation. This is not a substitute for professional medical advice relative to your specific medical condition or question. Always seek the advice of your own doctor for medical condition. Only your doctor can provide specific diagnoses and therapies.