Another thought, you might try Chinese Medicine to understand your fatigue more specifically to you. I have kidney qi deficiency, Qi deficiency, liver qi stagnation, blood stasis, and dampness related to my spleen. I've been working on these imbalances with acupuncture, herbs, diet, qigong, and trying to shift my attitude and ways of being.
I observed that my tongue looked bad two years ago, before I was diagnosed and knew that I had cancer. After the treatment finished my tongue looked like it was improving but then suddenly it got paler again. It turns out that a brain tumor was compromising my energy again.
If you haven't ever tried tongue diagnosis (a mainstay of western treatment in the days before all these medical tests, though without the chinese diagnosis) it is pretty revealing. Only a skilled practitioner can help you address and fully understand what is going on in your body though and how to address it. Try this tongue diagnosis tool:
http://eagleherbs.com/self-tests/tongue-diagnosis-38/