I've had many of the same symptoms for years, I put mine down to a dust mite allergy. It's the bane of my existence! :D
I'm very interested in your experiences of surgery.
I've often considered this as an alternative to antihistamines or anti-inflammatories like Flixonase. I don't think long term use of either of those is good for anyone. (Antihistamines being linked to dementia and steroids being linked to membrane damage amongst other things).
Anecdotally two things I link with improvements are religiously keeping my teeth clean including flossing to reduce gum inflammation and improving my hydration later in the day. Obviously there's a thin line to not drinking too much water and having that wake you up.