I have a somewhat different perspective. I work full time, and for the past 9 years have worked while using oxygen (my numbers are in the low 30's, high 20's) There have been times when I don't need the O2, but have been on it 24/7 for the past year to year and a half. I love my work - it gives me incredible satisfaction. I have averaged 1-2 hospitalizations during the past 9 years, and five or six bouts of IV antibiotics as an outpatient during that same time period. When I've been sick, I have reluctantly asked my pulmonologist if he thinks I should quit. His answer is that, of course, it's up to me, but that he wouldn't recommend making any drastic changes unless I just feel I can't work anymore. His advice has consistently been "You should just keep doing whatever it is you're doing, because whatever it is has allowed you to live an amazingly active life. You have far outlived your life expectancy." My work is like health food for my soul. I love it. I am a better woman, wife and mother because of the work I do. It keeps me active, keeps my mind focused on making a difference to thousands of people in the world, which, in turn, keeps my mind off my circumstances. I do fun and fabulous things with my family after work and on weekends and on vacations. My husband and kids are my biggest supporters. I have been blessed that everywhere I've worked, my bosses and co-workers have been supportive. I make no judgments about whether other people work or don't. It's a very individual decision. I realize that others may not get the same pleasure out of their work or may not have the same support system, or may have more serious health issues than I. But, I did want to let you know that there are some of us out there who have continued working into our 30.s, 40's, and, in my case, 50's.
For me personally, the few times I have taken extended leave to "build myself up" have never resulted in improved health. I have consistently made more improvement by going back to work. Maybe it's more psychological than physical, but whatever. It works for me. My advice would be to make your decision based on what you really think will help you. You're in my thoughts, and I wish you the best of health and happiness.