I Have Copd And Am Currently Doing Respiratory Therapy. My

i have copd and am currently doing respiratory therapy. my nose will get dried out and burn after exercise buf usually getz betterafter awhile.last week i got done with my therapy and i got the nose burning sensationback but tfhis ti e it did not diminjsh, i was breathing through mymouth for quite so e time and still am. nose and mouth persistwith dry and burning non ztop, i cant use my oxygen because it hurts. i can. breathe suitably but whyso dryand painful and persistent?