Every situation is different because every person is different
I've come out of CFS for the most part in the past year, but have suffered with it for 5+ years prior to that. My symptoms were pretty "textbook" -- migraines, not feeling well-rested after sleep, feeling like my internal temperature wasn't steady, and so forth.
Through consulting a kinesiologist we discovered that I had two major food intolerances: dairy and corn. Dairy is pretty easy to work around. Corn is another subject, because it's literally in everything. I firmly believe that corn intolerance is much more common than we imagine, and just because it's nearly impossible to get off corn long enough to find out if you're reacting to it. Medical Doctors for the most part have zero training on diet and these sorts of issues, and they are totally unprepared to give any useful counsel. If you're suffering from CFS and wonder if food intolerance/allergy might be one of your issues, I suggest consulting a naturopath and/or kinesiologist instead. They actually have training in these issues.
In addition to the food issues we found (through a hair sample test) elevated levels of some toxic metals. Aluminum and mercury were the worst. My advice to anyone with CFS is simple: remove all aluminum cookware from your house. Stainless steel and glass are safe, and little else is. Also, if you have metal filings -- have them replaced. The mercury in those amalgam fillings leaches out into your body over time.
The last item we've found is peculiar to my history. I grew up in Michigan during the '70s when the chemical industry accidentally dumped PBB in dairy cattle feed. I ate a lot of dairy at the time, and we believe that it was this that caused the dairy intolerance in the first place. (look at Wiki for the page on this for more info, if you're from that area). My kinesiologist found elevalted levels of PBB and also PCB. She's done work on me and within 5 minutes I smell like a chemical factory. Since my degrees are in Chemistry, I'm kinda used to the different smell of say, an ether, ketone or something vaguely aromatic. This smell was consistent with PBB. It's unfortunate we couldn't have gotten a sample and sent it to a lab for analysis. I would've been quite fascinated to see the result.
Well, enough of the details of my own experience. I firmly believe modern medicine's failure to find "a cause" for CFS is essentially this: there is no "one" cause. To figure this out will require a more holistic approach.
It's worth pondering that CFS is unknown in undeveloped countries. If I were a betting woman, I'd put my money on the idea that it's the result of environmental poisoning. This also would explain why women are more susceptible. We have lower body weight and come into much closer contact with toxic substances -- everything from cleaning products to beauty products has far more toxic stuff in it than you realize.
To anyone still suffering from CFS, I wish you every luck. Try to live as your great grandparents did and eliminate the unnatural things in your environment. Eat real food, the way it was designed for your body. Find natural cleaning solutions like white vinegar and borax and baking soda, and toss the toxic stuff away.
When your body tells you you have to rest -- just do it. If you don't, then you don't heal. You may feel like you are an invalid. Well, accept it -- you ARE. But you don't have to make that situation permanent if you give yourself the time you need to heal. Look on the bright side -- you're busy because you have kids? Put them to work! Our grandparents certainly did. Mine learned to do their own laundry and cook early on, because I simply couldn't do it myself most days. Now they are college age and very self-sufficient, and that's a good thing.
Keep your digestion going at all costs. Get more fiber with prunes, dates, or magnesium citrate capsules if you need to. Try to take digestive enzymes. Your intestines are probably pretty damaged by now and could use the help.
The article's advice on supplementation is also excellent, though again, I'd advise trying to find a kinesiologist or naturopath to help guide you through the wide array of supplements and target the ones you really need. In the end, you'll actually save money by not wasting on things you didn't need.