I doubt metal toxicity is the only cause of the adrenal fatigue. Stress, anxiety and neurotransmiter imbalances should be looked at on the top of the list.
Weak kidneys are also high up on that the list. If you look at TCM( Traditional chinease medicine) they don't even treat the adrenals on there own, they treat the kidneys and adrenals as one.
So there is probally a lot you could for your adrenals without chelating.