I know this is the "parasites:drugs" forum.. but have you tried inhaling essential oil vapor into your sinuses?
I mean like getting a boiling pot of water, putting a few drops of anti parasitic essential oil in, covering your head and the pot with a towel to keep the air in and inhaling it through your nose...After several repetitions of this and putting several rounds of a few drops, you can actually get a substantial quantity of essential oil way up in the sinus cavities that you cannot reach through dripping or nasal rinsing.
Young living is a good brand of oils.
Sounds like a grotesque problem to deal with. Hope you get better!