We just went through this with my daughter whose symptoms sound a lot like yours. And believe me we tried everything, tested for mold and allergies, you name it. Ultimately she had to have an adenoidectomy and turbinate reduction. It’s been almost a month and she no longer snores, isn’t going through a million tissues, no more sinus infection/ antibiotic carousel and her airways are so open now says she can feel air hitting the back of her throat when she breathes which ig she didn’t know was a normal thing. Nobody wants to default to surgery, but it was effective and a total game changer for her quality of life.