In addition to trying to eliminate sources you could see about trying to flush your sinuses.

There are two basic ways to approach this:

1. Sinus/nasal rinse or irrigation. You have to be careful here as using straight tap water can kill you due to pathogens and amoeba and such present that when inhaled deep into your nose can go straight to the brain. Either use the spray bottle nasal rinses from the store (tend to be best as they have some saline so don’t dry things out or sting much) or at least distilled water or water brought to a rolling boil for 5 solid minutes then cooled to room temperature and used same day to avoid giving time for anything to grow that might occur if you store it for days. But the idea is you flush/rinse your sinus cavities by forcing clean, sterile water up into them and getting the gunk out which can relieve pressure. Nettipots are one way of doing this but they have store sold spray bottles as well. In either case you put it in one nostril, concentrate, inhale and push the water up in there.

2. Spicy foods. You may have noticed in the past a time where you ate something so spicy that you got a nasal drip. Well it’s possible to eat quite spicy foods in reasonable quantities and cause your sinuses to clear a bit. If you like spicy foods this may be an additional option. You’ll be teary-eyed and miserable for some minutes but it can work. It isn’t just spicy foods, some intense mustards, horseradish, wasabi, etc can have similar sinus opening effects on many people if of the right potency.

And of course if you can see a doctor about this you can ask them. Steroidal nasal sprays often work, Flonase is the brand name but you can get it prescription generic for $5 usually which is cheaper than OTC.