First of all I am sorry to hear that you have been needing decongestants frequently. This is a very good question, but one that I cannot answer completely without being able to fully examine you, and take a thorough history. Thus I would recommend that you see a physician to discuss your congestion and history of frequent decongestant use. A primary care physician
would be a good place to start, however they may refer you to an otolaryngologist
(aka Ears, Nose & Throat doctor
). The first thing that I would want to find out, is why you have been needing a decongestant in the first place.
The differential diagnosis for nasal obstruction is very diverse ad can include everything from allergies to obstructive lesions such as polyps. It could also potentially be from dynamic collapse, such as nasal valve collapse. The way that topical nasal decongestants work (in very general terms) is by causing the erectile tissue within the nose to shrink down. They do this by causing vasoconstriction (blood vessels to tighten down/constrict). If they are used for a prolonged period of time (usually more than 3 days or so), your body will build up a tolerance to them, and withdrawal can actually make your nose even more congested then it was initially.
So I would definitely recommend seeing a physician to determine both the cause of your congestion, and whether your should stop whatever decongestant you are using. I hope this helps.