STOP using the over the counter nasal spray. It's the worst thing you can do. There's actually a rebound effect after you've used them that can cause your nasal passages to close up even more. I know because I had a year of sinus infections just like you it never went away and I did the nasal spray, antibiotics etc and finally went to a different doctor who told me to stop the spray and antibiotics.
This is gross but here is how I've been sinus infection free for 3 years....
In the shower I rinse out my sinus passages with a cup of warm water and a teaspoon of salt. I use a bulb (like the ones used for babies but the adult size), a fill it up with the solution, put my chin on my chest and squirt the stuff till it's empty into a nostril. Then I do the other side.
There is a kit that you can use to do this over the sink, but I do it in the shower with the bulb.
If you must use a nasal spray use one that is only SALINE, no drugs.
The steroids or steri pack is a good idea too to get you over the hump of feeling bad. But stop the nasal spray. Use the nose strips for nighttime, the Breath Right ones that open up your nose. If you work at home use them during the day too, it'll help you open up till you kick this thing.
When I have a cold, I steam my entire head over the sink, because I know I'm prone to sinus infection if I don't drain. So boil some water, grab a big towel and throw your head over the sink. It'll clean your pores too.