my husband was seriously addicted to afrin. he could not go or even sleep without it. after a few years he decided to quit. just like any drug, you will experience discomfort and maybe a few nights of restless sleep but it will get better within a few days. i think he took a sleep aid at night to help him sleep and then within a few days like ghilly stated above, the swelling will go down and you will begin to sleep and breathe better. it is like having a nasty cold for a couple of days!! Hope that helps a little. my husband did try the sleep strips but did not work for him, however, it might for you. hope all goes well.
If you just stop using the nasal spray, you will go through a period of about 24 to 36 hours where your nose will be almost completely blocked up from the mucous membranes swelling with rebound swelling, but if you can tolerate that 24 to 36 hours, then the swelling subsides, and within a couple of days you will be breathing normally without the spray.
It will be uncomfortable for that day or day and a half, but once the swelling starts to go down, it does so fairly quickly, so you'll only feel stopped up for that short period of time. Just pretend you have a bad cold. During the really stuffy time it helps to put a bit of Vicks Vaporub or some other mentholated substance on the edge of your nostrils, and blow your nose often because for some reason, that seems to help the swelling go down more quickly.
I am not sure what you can do I would suggest switching to a decongestant in pill form, If not talk to a doctor or pharmacist they might be better able to help.