I Keep Getting Green Snot Out Of My Head. This

I keep getting green snot out of my head. This has gone on for years. I've had every antibiotic you can think of. I've had sinus surgery to fix a deviated septum and to remove a pollup. I'm on allergy medicine, but this still continues. My ear also hurts on one side and I tend to have a lot of drainage. Antibiotics clear it up, mostly, when I am on them but it always comes back within days of finishing them. Any ideas as to why?