Seeing an ENT is the best place to start. You never know what else you may be dealing with...infections, tumors, polyps, 3" nails from the errant nailgun, etc.
If its turns out to be " just allergies" one of the best ways to treat a major SOURCE is.....a vacuum.
Seems a lot of us sinus sufferers have a big problem with >>> The Dust Mite.
Millions of the little arachnids are having a party in your house, bed, pillow, chairs, carpet (feeding off the sloughed skin cells we leave everywhere) and it is their excrement and exoskeletons that we have a problem with.
Google "Dust Mite" and you'll see what I mean. That vacuum needs to have a HEPA filter or you're wasting your time. Hardwood floors and those special mattress covers piss off those critters too.
Several other options available.
Just so happens there was a local TV interview of a "super-allergic" kid...found out it was the dustmites....went so far as to putting all stuffed animals in plastic bags and freezing them for 24hrs to kill the little critters.
Just passing along info.