For most of my adult life, I was "addicted" to sudafed (pseudoephedrine, not phenylephrine). I had absolutely horrific sinus problems. Could never breathe, tons of sinus infections, etc etc. Things like sinus rinses (not a netipot which is gravity driven, but a positive pressure squeeze bottle) helped, but it was still a major inhibitor in life.

I got a new ENT, and I started getting a quarterly "chemical nasal cautery". It has ABSOLUTELY changed my life. I can breathe sooo much easier, and I couldn't recommend it enough to anyone with persistent sinus issues. It is super easy. It doesn't even kind of hurt, the most mild of stings if anything at all. Doc will spray a lot of afrin up your nose, then lidocaine, then carbolic acid which kills a bunch of your immune cells (so they can't overreact to tree pollen and make you miserable). You get it done once a month for three months, then once every 3 months thereafter.