Before the stock response of "go to a doctor" abounds, I am going to one, I just won't be able to until a few weeks from now and I want to know as much as I can in the mean time.

Since roughly two months ago I can only fully breathe out of one nostril at a time. The other nostril is mostly blocked. This leaves me with about 60% of my full capacity to draw breath. The weird thing is, the nostril that's blocked and the nostril that's open switch roles at seemingly random times. The only pattern I've been able to deduce is that sneezing changes the arrangement of blocked vs. unblocked almost every time.

The only thing I can connect this to is having my nose broken (and never set thanks to the advice of the supposed EMT who was present and my own ignorance) about two years ago, but I found it strange that it my nose would just now be showing detrimental effects.

Any clues?