I have a pain&pressure in my upper jaw i also have pressure near my temple. it really only hurts when i open my mouth or try to chew what could it be?

TMJ/TMD: It sounds like a problem with your jaw joint(s) most commonly referred to as TMJ/TMD. Having said that, it would be prudent to be evaluated by a local dentist to confirm this diagnosis and suggest both palliative treatment now and steps to eliminate and prevent future problems. Left untreated it tends to become more problematic over time. Seek a dentist who has experience & training in this area