My jaw is always popping but its not tmj...also i feel preure in my head i hear like something in my ear.?

ok my jaw pops when i yawn its not tmj i went to dentist...ive had a catscan and a mri and they both came out ok but i still feel like preure in my head....exp when strain to lift a heavy objecdt i get very light headed and tired. i need help i been to a doctor,dentist and even a nurologist and no one can help me sometimes i feels like a pulled muscle or a cramp but in my head....please leave serioius msgs thank you