I run out of breath when I climb stairs and sometimes in the night and when am forcing myself to breath, my chest pains alot... What could it be?

Dysautonomia - MVP . You may have dysautonomia which is associated with mitral valve prolapse syndrome - neither are usually life threatening but both cause patients anxiety about their symptoms. Read dr. Richard hoffman's book on mvp on amazon.Com. Increase fluid intake, try magnesium supplements.