Hi, Thank you for providing the brief history of you. As you have fibromyalgia and sleep apnea, this two things are really painful which i can understand. Using a BIPAP machine always and chest pain, its really painful. As your PCP mentioned you have costochondritis it could be possible as due to atelectasis of lungs the respiratory system has to do additional work. Atelectasis is partial lung collapse or inflammation of the lungs, depending upon the area and lobes. Also, as you had fibromyalgia, now oxygen therapy will help you reduce the pain as well. BIPAP is used as the current lung physiology is not great enough to support the body. Also, you need to be patient here, as the atelectasis will take a little time to allow healing. Since the lung is inflammed in the x-ray, it needs the lung tissue to recover and which will be a slow process as well. Understanding the daily cases seen by me in my clinical settings, i really see that how beautiful the body is, the healing process happening is so beautiful that it is unimaginable. Any injury to the body takes times to come and it will even take time for the body to heal. In the duration of the body to heal on its own, the support system is provided by the medical professionals. Rest is totally depending upon the bodys natural process to heal. No one can boost it no one can delay it. Now, coming to create a support system in the form of therapy, i will advice you to perform breathing exercises along with BIPAP machine and also do some general body exercises as well. Body needs its metabolism to be active again and this can happen with your own self effort. Also, the support system is on, so your effort will help boost the bodys natural mechanism of healing. Regards Jay Indravadan Patel