I've experienced substantial reduction in my allergies by doing a couple of things together.
One is taking nettle as a tea. It can also be taken in pill form, but I had better results with tea.
The second was to reduce my exposure to irritants. There is a theory that rather than being a specific response to a specific allergen that always happens in the same way, allergic response depends on the overall load you are placing on your system. It's like filling a glass near the top, You only notice it when it overflows, and if you dump some of the water out you can still add some without overflowing. So if you reduce what other things might stress the system you will get less of a reaction.
I kicked my dog out our bedroom, enclosed my matresses with dust mite covers, got my partner to do the vacuuming 8 hours before I would be in the bedroom. I started washing our sheets weekly in hot water, or with an allergy resistant spray. I had the carpets professionally cleaned and treated for dust mites.
I eliminated dairy from my diet. I will still eat cheese from sheep or goat, and get buy on soy for everything else.
The last thing I did, which is useful even if none of the above is of interest, is that during flare ups I did a saline rinse of my sinuses. You need a 1/4 tsp of salt to one cup warm water, and then you can snort the mixture, use a bulb, or a neti pot. I never got the hang of the netti pot. I did this twice daily for a month then just when things got bad.
Over time all of this helped enormously. We just had a spell here where everything bloomed at once, and I had no problems.
I hope you feel better soon.