I was diagnosed with CFS at Stanford years ago and helped fund the Robert K. Naviaux 2016 metabolomics study. I had a myriad of symptoms and played wackamo with them for years while seeing dozens of doctors. I always knew my problems were related to sleep but didn't know if it was cause or effect. In the last few years I came to discover I had a low heart rate during sleep which was starving my body and brain of Oxygen while sleeping. I finally convinced my doctor and cardiologist it was responsible for many of my problems which were worsening. I had a pacemaker implanted 3 weeks and most of my bodywide problems have resolved and I feel much better. Anyone with sleep related ME/CFS symptoms should make sure their heart is supplying enough Oxygen while sleeping. Lack of Oxygen can cause symptoms everywhere and since doctors operate in specialties, they often don't have a clue that this is the actual problem. They typically think you have sleep apnea but if you test that you don't and its your heart rate while asleep, its a big problem getting help.