I woke up at 5 a.m. and could not get enough breath..I think this is what is called hyperventilation..constantly trying to get enough air, taking deep breaths one right after the next, but always feeling like the inhale cuts off before the full breath, so it is not enough. sometimes this makes me feel like I need to yawn constantly as well, but cannot complete the yawn either..it is very uncomfortable and terrifying..it really makes minutes turn like hours. Anyway, I decided to take a sudafed allergy tab and it actually seemed to help. Has anyone heard of this or used them to help anxiety?