Moist air is easier to breathe, also needed by the body as the process of breathing difficultly heats up the body and dehydrates it. The best way is a cool mist humidifier. Short of that, use the steam from a tea pot or such, with a towel draped over your head and the top of the pot, or sit in a shower of steamy water... and breathe deeply.

One thing to try when you are not struggling to breathe is to strengthen your lungs. Swimming is wonderful for this. Then, when breathing really becomes a struggle, your lungs will perform better.

Is the problem with the lungs themselves or with the bronchi? Have you tried cortizone or a derivative of it, to reduce the swelling in the bronchi and thus aiding breathing? Decadron will do this well.

What does your doctor say?

But you know? When all else fails... the cool O2 at the hospital feels great!