You'll need to learn about the pituitary and hypothalamus.
Learn about secondary adrenal insufficiency.
Yes, there are some very heart warming stories from people with Chronic-Fatigue-Syndrome who got very welcome gains very quickly when they started on adrenal support. A female friend's experience was not so dramatic but the effects have been impressive.
Mercury can cause or contribute to such symptoms, especially the organic Hg in fish and some vaccines.
If you also have a list of other symptoms--mood problems, messed up gut, weak muscles, maybe tinnitus, tingling in hands, MCS you might consider the possible involvement of heavy metals.