Hi and Welcome to HealingWell, Radha21!!
Not always, but frequently when you have sinusitis problems and have been through the gamut of med.'s like you've had to do, it seems more like a 'chronic' condition.
A lot of these troubles can be brought on by allergies, especially by perhaps molds. I know you've said that you've tried pretty much everything...but sometimes if it's from an actual allergy, it can be treated with allergy injections, steroid nasal inhalors, etc.
It can also be brought on by viruses and bacterias...Have they ever tried you on a course of antibiotics?
I hope I've given you 'food for thought', Radha and that maybe it will offer you some help.
"Because he is he and I am I."......E. V. Lucas