Hmm. Must hack my breathing.

Breathing has been sub-optimal these past few days. It seems I run out of breath so quickly, and when I do breathe in, I don't get the feeling that I'm breathing all I can. When I try to breathe deeply enough, I get a little faint. I don't smoke. I don't slouch. I walk a lot, although I'm going to increase my amount of exercise soon. I need to get to the bottom of this, as it's not the first time it's happened...