When looking and in lying position, sinuses become inflamed. Why?

For the last year, when I even have a slight downward tilt to my head and when I lay down, my sinuses will become inflamed. This inflammation further leads to pressure building, painful eye movement, headaches, cognitive slow downs, and an inability to sleep or do basic daily activities without great pain.

I have been to the ENT, from day 1 they were uninterested in hearing my symptoms. I did have a CT scan, nothing showed up. However, the CT was taken when my head was at a level position - not at a position that symptoms appear. Also, prior to seeing ENT, I had been diagnosed with a sinus infection. ENT said this wasn't the case though.

Things I have been doing to help alleviate some pain, with short-lived success (I am still doing these things, the efficacy of this just slows/stops eventually): *sleeping with head elevated; *using warm water to bring mucus into nose and then using nasal aspirator; *ibuprofen; nasal sprays (antihistamine, *steroids, saline, combination); migraine pills; decongestants; mucus thinners; etc. *Starred items work best, but still not perfect.

Before sleeping with my head elevated, I would also have a ton of post nasal drip with an extremely dry nose. I still have the dry nose, but no longer have the post nasal drip.

I need to drink more water and get more sleep. I believe these things will help. However, I am worried that even when improving these things, my issues will persist. Why would my sinuses be inflamed when looking down and lying down? My environment hasn't changed at all recently, I have never had allergies before, and the onset of these issues was very rapid (prior to a year ago, I was just fine).

For context, if this helps -- I do not smoke, I drink very occasionally, and am 26 years old. The ENT also noted, but did not discuss with me, that I have Concha Bullosa.