I was additcted to nasal spray for years as well. The only known, proven way to break it is, indeed, to go cold turkey. It takes three days. And it works! It will not be easy. You have to treat it like you would a bad cold. Take off work if you have to. You will lose sleep, your nose will stop up, it will drive you crazy. But after three days, you will have broken the addiction.
Thereafter, if you absolutely must use a nasal spray, never use it for more than one day. If you have the need a second day, use saline mist, so that you at least are alternating days. But try to avoid ever having to use it more than one time.
Good luck! Most people have no idea what a true physical dependency/addiction this is.