remember you have an illness which could be related to the issues your suffering - fibromyalgia can kick in and cause issues that a cyclist wouldn't know about or help you diagnose. Be Careful, take your time and know your limits.
casing point being, my partner suffers the same illness. I remember last year my partner waking in up feeling great, decided she wanted to go shopping for the day, had breakfast, got dressed and jumped in the car, during the drive to said generic shopping centre, she became quite fatigued, painful and very sore. next thing i know we've done a 150mile round trip and not seen a shop.