The only thing that helped me was seeing a good ENT. It took several different visits to different ENTs, because while they all identified my issues were structural, I was told surgery wouldn't help.
I finally was able to get reconstructive surgery, which included removing a bone spur that had grown big enough to almost completely block my left sinus, as well as a reduction of the turbinates on either side.
Probably the most brutal recovery period I've ever experienced, because I was breathing through tubes that were basically airline hose for about two weeks, but when they took everything out and my first breath of cold air hit the back of my sinuses for the first time... all worth it.
No on/off sinus infections or sinus issues since then.