I know it's been a few years but for the sake of people who read this, I am just putting a quick note here as to how I've recovered from this.
After using 23andme.com to get my raw DNA and plugging it into mthfrsupport.com, I have found that I have a number of gene mutations. The primary mutation is with the MTHFR gene which means I don't methylate very well. This impacts many downstream processes including my ability to stage I and stage II detox in my liver. So over the years, every time I've been exposed to toxins or heavy metals, my body wasn't getting rid of it. In January of 2016, I could not longer work because of this. After some serious diligence and an excellent kinesiologist, I have been well enough to go back to work. In fact, I haven't felt this well in quite some time.
If you are struggling with fatigue of any kind, I implore you to check your genes and start treating your deficiencies with nutrition.