I had the CFS dx for about a year and a half, didn`t seem to fit real well, but not really enough differences to question it too much. The dx from my pcp and an infectious disease specialist.

It wasn`t until I started walking really bad that my pcp started thinking something else, and ordered a mri, further mris confirmed MS. Have you had MRIs?

Fatigue for me was non stop, and got progressively worse.