I am having trouble breathing Help?

Im 18 and I have been dealing with this ever since I was about 10. I think I have a breathing problem. I don't smoke and it fells like I am out to breathe and I have to yawn to fill up my lungs. It's almost like I don't exhale out of my mouth only my nose(mouth closed) Whenever I try to fill up my lungs by yawning when loud music is on or someone is talking it doesn't work and I get frustrated as I try to yawn and fill up my lungs. It feels like there is a bubble in my lungs or something, its hard to explain. As I type this I have to yawn here and there to get my lungs full of air. Help me please,