"I've already experienced many paradoxical reactions to thyroid medication, vitamins and herbs. The risk of DHEA supplements (even in small doses) may not be worth it, I can't regress."
This is why I so often mention low dose pregnenolone. It is upstream from both DHEA and cortisol but also has a good reputation for its helpful role in the brain. http://en.wikipedia.org/wiki/File:Steroidogenesis.svg note DHEA is not abbreviated.
10mg caps of preg are quite inexpensive. Maybe you could start with just 10mg at lunch. Eventually you might like another 10mg with a mid afternoon snack on very stressful days.
Assuming you were not amped up on the day of the test I would not expect adrenal fatigue to be the only issue for someone who is struggling with lots of fatigue.