Have you considered changing your diet? I had debilitating allergies, asthma, and eczema for two decades. On all sorts of pharma inhalers, steroids, and anti-histamines. Went keto-vore and all of it’s gone.
I highly doubt it's diet related. I eat pretty well to begin with. I just live in a place that has extremely high grass pollen. And after living here for 30 years, my body was like, fuck you, you have allergies now.
I personally lived through it and can attest to it. You are under no obligation to heed my advice, but might be worth just trying out and seeing how it goes.
I honestly don't know what I would change in my Diet. My avoid vegetable oils, I eat a pretty balanced diet of meats and veggies and i shop, as local as possible.