Robert it is good to hear about your gains in the fight against CFS.
I know an older man whose blood sugar--HA1C--marker was gradually worsening over the years to borderline diabetic. A couple months after starting on 100mcg or so of Cr daily with his largest meal of the day the HA1C dropped to center of the normal range!
A couple years later another HA1C was still in the normal range although closer to the prediabetic range.
I think Cr helps to move insulin into cells.
You should not expect corrupt insurance doctors to mention such things.