I need Flonase (available as generic) once or twice a day because my nasal passages are too small. If I skip a few days I don't notice any withdrawal at all. Maybe you could switch to that one while you wean off the other.
I have had a sinus infection for a year and a half, or maybe just get them once a month or so, but it seems like it really never was really cured. I've been on Bactrim for 3 weeks, now stopped, taking Diflucan which is helping the most.
I also rinse daily (use a very small teapot) with my own mix of 250 ml (1 cup) water, 1/2 tsp salt, 1/2 tsp baby shampoo. I have a nasal spray made with 45 ml (3 Tbsp) saline, 5 grams bactroban nasal ointment. I put it all in a glass cup, heated 30 sec in microwave. This left the parafin mostly on the walls of the cup. I put it back into the spray bottle and try to spray once into each nostril with my head down to get it to the sinuses.
I suspect I have a chronic "biofilm" or plaque left in the sinuses which even the surfactant baby shampoo won't completely remove.