Is it possible for tmj and allergy symptoms to be related? i have clicking of the jaw, constant congestion and strange head sensations. should i worry

Possible: There is no way to know for sure without a complete examination and review of your medical and dental condition. It would make good sense to have this evaluated by your dentist and physician.

Some connection: Muscles can go into spasm and dysfunction and block flow of fluids through portals such as the Eustachian tubes.

No: There are two separate entities although TMJ problem can give you a sense of the ears being plugged when no obstruction is present. See dentist to get you a mouthpiece to wear at night.