How do I deal with chronic facial pain?

Depends . It depends on type of pain you have. The best advice is to see a specialist ( neurologist or pain physician ).
Jaw pain. Temporomandibular disorders, jaw pain, orofacial pain are terms which denotes chronic jaw pain problem which is not due to any dental pathology. Your complaint is possibly due to temporomandibular disorders. Try warm compresses over the jaws and temples along with self massaging; mouthguard often help. Advil/tylenol is also an option. You can contact an orofacial pain dentist ( www.Aaop.Org).
Facial pain. There are various medications such as neuropathic anti-convulsants that may be extremely helpful. Newer surgical options may provide relief for trigeminal neuralgias. Need to find the cause first.
See Expert. See a orofacial-TMJ expert for diagnosis and recommendations. Any dentist can be a TMJ expert with the proper training and experience. Most commonly, oral surgeons, prosthodontists, and orofacial pain specialists. Ask your MD, your dentist and your dental society for referrals.
History and exam. Vague. Cannot answer without a thorough history and exam. I would see a dr. Asap. Need to have knowledge of the ailment and the severity and potential treatments. Could be a tmj/tmd issue.