I have sinus real bad cann't breath unless i use my nose spray went to the doc got a ct scan came out with one sinus being infected. been on med for months still don't help tryed every thing help...

It may be that the infection has inflamed the blocked sinus to the point where it can't drain, which causes the infection to flare up again as soon as you stop the antibiotics.

You don't mention what type of nose spray you're using but usually when you get to this point the doctor will prescribe a nasal steroid spray to help reduce the swelling along with a short course of oral prednisone (also a steroid) to help open things up and get them draining.

You should also consider irrigating your sinuses using a SinusRinse bottle (available at any major drugstore chain) or neti pot. Irrigation will help get the infected mucus and any irritants out of your sinuses.

Finally, once you get this cleared up you should work with the doctor to figure out what's causing the irritation - if it's allergies you have to manage the allergies to keep your sinuses from getting inflamed and causing the cycle to start all over again.

Hopefully that helps.