I've spent tye better part of the last 4 years focusing on adrenal health by taking adrenal supliments, cleanses & flushes & receiving energy/emotional work. If I missed a day of suppliments I was usually ok; but, I couldn't miss more than one day without feeling exhausted.
Something that I've learned & wished someone would have told be sooner is that the relationship between the adreanals and the thyroid plays a huge role in fighting fatigue & healing the adreanals. I've had my thyroid tested a couple of times over the years and have been told that it was a little low; but, it was because of my adrenals so the focus of supplimentation was always on adrenals. Like you, I noticed troubles with digesting certain foods & some would drain my energy to the point of needing a nap.
In hopes of finding a better solution to all this, I recently began working with a homeopathic medical doctor who also noticed the low thyroid so he added some natural thyroid to my supplimentation along with adrenals. It has made all the difference in the world! I have also began juicing for my thyroid and adrenal health in hopes to be free of suppliments & have noticed a lot more success with the juicing now that the thyroid is is being addressed as well.
I don't kniw if you are still looking for answers; but, if you are, having your thyroid checked & supplimented may help you. My doc said that the perscription thyroid doesn't have any live active thyroid, so its important that if you do take it to make sure it live. Also, Iodine (non salt soures) has played a huge role in combating fatigue since its food for tbe thyroid.