I struggle for a satisfying breath, but am unable to find it. I constantly strive to find it by inducing a long sigh/yawn but most times feel myself fall just short of catching a full breath. Even with the hands behind my head, I cannot get a full breath every time, in fact I fail most of the times. This has kept me up at night several times. I am a 22 year old college student who less than a year ago was capable of running 5k's or a sub-6 minute mile. I haven't tried this recently, but would guess that it is out of the question now. Also, I stopped smoking cigarettes a year ago so I was able to do the athletic achievements I mentioned while I was still smoking cigarettes and marijuana on a more than daily basis, but have shortness of breath once I stop? Please help me!