Some cold turkey advice
I have had several periods of nasal spray dependency in my life, sometimes lasting for years. Most recently I started using it in December when I caught a cold and couldn't bring myself to come off it.
Some days are worse than others for nasal congestion, so when I woke up 3 days ago with relatively mild symptoms I decided it was a good day to start the cold turkey process. I'm three days in now and basically back to normal. I think picking a good day to start really makes a big difference. If you wake up with your sinuses completely swollen shut then you'll have a worse time of it. Also, always start the cold turkey from the moment you wake up - you've already got all the time you were sleeping behind you at that point.
Just remember that having a blocked nose is not the end of the world and it does get better pretty quickly.