I think tying allergies to this research probably takes some effort. I will say, as someone in a similar boat, that I've gotten a lot of benefit from regular ol' allergy shots, as well as from low-grade steoroids like fluticasone when things get intense.

Separately, if you haven't heard about it already, only being able to breathe clearly out of one nostril at a time is normal, and helps your nose do its job well[0]. You may be noticing it more acutely because of your congestion.

0: https://en.wikipedia.org/wiki/Nasal_cycle