I have beendealing withthis for a year. The only thing that helps me is t do yoga. It might sound far fetched, but the posture and breathing exercises will open up your lungs. It is most likely due to having a concave chest, from bad posture. Tai Chi and Yoga have specific expercises for relaxing the shoulders and upper back and opening the lungs/chest area. It is seriously the ONLY help I have had, for ot being able to get a full breath of air.