I read your post about all of your symptoms and I am really sorry to hear that you have been struggling for such a long time. On the other hand, that is exciting that you have already had quite a bit of improvement. I don't know a lot about the Body Ecology Diet, I went on their website and they didn't really have any specifics on what it entails. I guess they want everyone to go buy the book.
The first thing that I thought when I was reading about your symptoms was that your intestines could be inflamed due to poor diet choices. Sugar and white flours can be very inflammatory to the intestines and just cutting out these should be very helpful to you. My one piece of advice is to be careful with cutting carbohydrates. Many popular diet plans are advocating high protein, low-carbohydrate ratios for eating, and while some people do okay on these, for other people it can do more harm than good. For example, we know that fruit contains Sugar which may be inflammatory but they also contain fiber and micro nutrients that are vital for our body. Elimination Diets are great, you could try making your staple foods brown rice, chicken breast, and plenty of raw and cooked vegetables, as these are some of the safest foods and the least likely to cause inflammation.
Regarding the foods you asked about coconut oil and ghee are some of the best fats to use in my opinion but I would use these and other fats in moderation because more fat means more work for the liver and since you suffer with constipation that could mean your flow of bile is impaired. Apple cider vinegar is great and can be used instead of other types of vinegar on salads.
Keep looking around on curezone and if you haven't already, read the candida homepage link on this site and read all of the links in that text as this is the best advice for improving and correcting health without all the hype of some of these modern diet programs.