Clogged left ear, gets worse with allergy chgs, causes migraines. Had ear infec first time ever 3 years ago, has never been normal since. What to do?

See an allergist. You may benefit from allergy injections. I recommend that you see an allergist for skin testing to see if allergies are truly a cause of your symptoms. If so, medicines can be customized for your needs. If the meds fail then injections may be needed.