I use a neti pot or saline spay often durning the spring and fall. For last few years flonaze has helped a lot too. An air filter and staying away from smoke helps too.

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.

Get set up with an ENT (Ear Nose Throat) specialist.

They will take a look at your sinuses and probably get you tested for allergies.

From there they can come up with a plan that may be as easy as getting rid of pillows you’re allergic to, drugs, or surgery.

Eat local honey.

Local bees make honey after having bee sex with the local pollinators and birds, or so I'm told.

But no, getting small inoculations of local irritants helps many overcome these sorts of reactions.

Ymmv.

Wash your hands more. Clean commonly touched surfaces with disinfecting spray (mouse, keyboard, door handles, etc)

Do you have a house? Do you regularly change your furnace filters? Is your house over 10 years old and had the ducts cleaned?

I know a guy that would get sinus infections yearly and had his ducts cleaned, problem went away. He was rather extreme and does it yearly, but it works for him and spending a few hundred a year is worth it to not have sinus problems every year.

What helped me was to eat better. In general my health improved by getting further away from a SAD (Standard American Diet): no meat, only occasional fish, lots of vegetables, much fewer processed foods. But what might be the most important was to replace sugar with local and/or unfiltered honey. (Maybe its pollen immunized me from certain allergies that started the infections?) I haven't had a sinus infection for months, almost years now.

My mom used to be like this and the only solution was surgery. Worked very well though.

If you do want to go the route that others have suggested, NeilMed sinus rinse is better than a netipot.

Have you tried clearing your sinuses with a netty pot or similar?

deffo see an ent. there might be a bean that you shoved up there when you were a child