I thought it is important to highlight the limitations of that Lancet study to other fibromyalgia patients. Here is an extract from the NYT article which may help you to explain to your doctor why pushing you to exercise might not be the right thing to do:
The British scientists who conducted the research identified study participants based largely on a single symptom: disabling and unexplained fatigue lasting at least six months. But many researchers, especially in the United States, say that definition takes in many patients whose real illness is not the syndrome but depression — which can often be eased with psychotherapy and exercise.I tried to push myself to exercise when I was not ready for it, and on every occasion, that resulted in a bad "relapse" - miserable days in bed, symptoms all flare up.
Today, I am relatively well . Sometime ago, I had given up listening to doctors who did not listen to me, and listened to my own body, and started my own "programme". That was the start to better days.