Congested in one or both nostrils constantly my entire life until I started using nasal spray, now I'm completely addicted to it, is there any kind of treatment I can get to breathe normally?

(19, afab, 5 '1, 175 lbs, white) I have been a chronic mouthbreather my entire life. I thought it was normal to not be able to breathe through your nose very well at all, either 1 nostril or both being mostly or completely blocked with no other typical allergy symptoms. As a kid my gums constantly felt raw from breathing through my mouth and air hitting my teeth. it's a dry congestion, blowing my nose never helped at all.

3 years ago I discovered nasal spray and started using it and it actually helped. Finally I didn't have to hold my breath when I chewed food 60% of the time. The problem is I literally cannot come off of it. I've tried to put up with the rebound congestion and stop using my spray for several days and it doesn't just go away. I used to just use it in the morning and before I went to sleep but now I have to use it like every other hour. I know for certain if I just cut it off cold turkey it will not make my congestion go away because I've had it long before I ever knew there was a way I could get relief from it. But I don't know any other way I can deal with it, because especially now that I have finally known what it is like to breathe clearly, I cannot go back to mouthbreathing, I just can't.

extra info: I take an allergy pill daily (zyrtec or claritin I can't remember which it is right now but I've switched between both many times and it's never helped my chronic congestion) but otherwise not on any medications. I don't smoke or drink or anything either. I'm suspecting it might be a deviated septum.

I've never been able to get anything checked out at the doctor because my parents have some.... unique "beliefs" on medical care and never listen to me or take me seriously when I've expressed concern over my own health. I've also had constant headaches like, most of my life, bad circulation, brain fog, trouble standing for long periods, weird stuff with my knees seeming to pop in and out of socket sometimes and it's very painful, etc. Don't know if these things could be connected to my sinus issues at all but it might be worth throwing in. Done a bit of my own research on these things and I'm trying to manage it the best I can but of course I can only do so much without actual medical help. Since I'm an adult now I've thought about trying to take care of this stuff on my own, if it is possible. if anyone knows something I can do to help besides just continuing my nasal spray addiction, it is much appreciated, thank you!