Is a septoplasty likely to improve my breathing? (photos)

29M, 6", 90kg. I have had issues breathing through my nose since I was a teenager. I can only ever breathe through one nostril. It is at its worst when I lie down and in humid weather. I find that after swimming I have water trapped in my sinuses that sometimes does not drain out for days. Steroid sprays do not work at all, especially since I can barely inhale through my left nostril. Decongestants work, but I do not use these as long term use is detrimental. Nasal rinses have not help.