Sculptor 44, my heart goes out to you, I wish I had words, but no matter what we are going thru, we are on our own paths with what we are challenged with. I always thought 90% was good for oxygen. I do deep breathing on that issue for myself. I saw my neighbor last night, attempting to walk her little dogs and she has pretty advanced pulmonary issues, and it all got worse for her with the onset of RA about 5 yrs ago, prior to that a strong woman. She also mentions that she has post polio syndrome issues. Didn't plan to talk about her but I know her and hearing your story I chose to mention her. Do you meditate, silent meditation can do so much. Loving thoughts to you.