Whenever i open my mouth my jaw hurts and i can feel the pain on the back of my ear. what do you think it is?

See Oral Surgeon: This sounds like a problem with you tm joint. You have likely been wearing down the disk in your joint over a period of years, and now the damage is manifesting itself as pain. You should see a dentist and an oral surgeon to determine what is causing the damage (likely grinding and imbalanced bite), so that you can minimize further damage.

Jaw Joint: TMJ problem likely. Other TMJ symptoms include, painful chewing, joint noises, headaches. See an oral surgeon for confirmation If TMJ, ask for referral to TMJ specialist.