Anyone have sinus issues after workout?

I have found that the evenings after I swim my sinuses shut down and I have to hit the Afrin in order to breath and to avoid snoring all night (otherwise my wife kicks me to the basement). I swim in a bromine pool - grew up swimming in chlorine and didn't have this issue. I hear that long-term use of sprays like Afrin will eventually melt your brain. So I need to find an alternative - anyone run into this? By the way, I've seen allergists and regular doctors. The allergist told me the bromine is an irritant and I should avoid swimming - not much of a choice. The doctor gave me some saline spray that doesn't work.