Sometimes just some mildly swollen nasal passages will make you feel an effort to breathe, so you can't zone out, so things start getting emotional and you start breathing more agitatedly, the senses become more acute... you get caught in a loop that spirals into something that it wasn't when it started.

At that point, I know it's an uncomfortable but wise strategic move to get up, go to the bathroom, feed the cats, do something or even just stand up, erase the mental/emotional whiteboard and start again.

I'll turn on something mellow but arid on tv - like a BBC documentary on the Byzantine Empire - and keep an eye on my breathing, slow it down. At some point I can feel the nasal swelling subside by itself, and I try again.