Back of tongue is sore, i pull it to the side and feel pain. feels like my gum is sore and pain to left jaw, started a day ago.

See a dentist!: There could be many causes and merely listing some possibilities will not be helpful. Please see a dentist for an evaluation.

Vague- many reasons?: Hard to determine without a thorough history, exam and possibly some tests. See a dentist or preferably an oral surgeon

See a dentist ASAP: for evaluation, oral pathology screening, x-rays and treatment options.

May be: May be as simple as a sore throat. If pain persists beyond a few days check in with your Physician.