PAIN in left side of face/jaw area. What is going on?! Been to several different dentist. Desperate for an answer.

There are many possibilities.  I would suggest either a trial SPG Block or a  diagnostic neuromuscular orthotic.  Have an endodontist check tooth carefully.  Could be referred pain.Most common cause of pain that continues is Myofascial Pain and Dysfunction or Sympathetically maintained Pain.  Please check weblink for patient testimonials.Ira L Shapira DDS, D,ABDSM, D,AAPM, FICCMOPast Chair, Alliance of TMD OrganizationsDiplomat,  Academy of Integrative Pain ManagementDiplomat, American Board of Dental Sleep MedicineRegent & Fellow, International College of CranioMandibular OrthopedicsBoard Eligible, American Academy of CranioFacial PainDental Section Editor, Sleep & Health Journal
Member, American Equilibration SocietyMember, Academy of Applied Myofunctional SciencesMember, Academy of Cosmetic Dentistry

Hi:This is can be as a result of Trigeminal Neuralgia.  You should consult with a neurologist.Best,Dr. Maddahi