I need a little help

I am having a really hard time falling asleep. I get this full feeling in my chest and throat like I need to yawn or take a deep breath but I can't. I also cannot stop yawning until I get the "satisfaction" of a deep breath. Once I finally get a deep enough breath 3 seconds later I get the feeling again. I am so uncomfortable and I don't know what to do. It happened once in a while before I was pregnant but now it is when ever I am relaxing or going to bed. Anyone know why or have any suggestions?