I regularly use a saline nasal spray and that is what I used during the night when I wake up (like at 3 am) and have trouble breathing - usually just on one side.
I have also used the neddie pot (think that's the spelling) to flush the front sinus areas. I can't say I've noticed any specific improvement with the neddie (or maybe nettie) and haven't used it in the last several months.
i used to have what you are describing before my body started reacting in the form of developing the itch and post nasal drip.have you ever tried flushing your nose regularly during the day with salt water? (1 tsp of salt dissolved in a glass of boiled cooled water). prepare and keep covered. Take some in the cupped palm of your hand and inhale gently letting it hit your throat and trickle out of your mouth.i think it will help your sinus issue. also, try to inhale steam as much as you can. both remedies will definitely help you.i do take antihistamines when it gets unbearable and keep trying to find alternatives that can help. i agree that there is something that i have to discover and avoid.(symptoms definitely improve when husband is not around!)
My problem is a chronic congested sinus, only when I'm lying down - disrupts sleep. I've used a couple of prescription nose sprays, they don't help much, but the "can't use for more than a couple of days" Afrin over the counter works great... strange.
Sounds like your problem is much worse, and hits you 24/7 as I understand your post.
The only permanent cure I have heard of is finding what causes the problem, and eliminating that from your life (just hope it isn't your spouse). I understand you've tried and failed..maybe you should continue to try while taking antihistamines for some relief in real-time.
I don't know what the downside of antihistamines is, but there are many offered so you must not be alone in your suffering. Look for the low cost one that works. As noted in my case, I get great relief from "Afrin" but I don't use Afrin I use the Walmart clone at about 1/2 the cost. All doctors I have talked with about my congestion (my primary care mostly, but also my cardiologist, and now I have a Pulmonary Doc too.. haven't seen an ENT yet).