In a way you are lucky you had high Hg on your hair test. It is actually much more common to find very low Hg in hair. Hg fouls up transport/movement of many minerals. If you look through the hair tests at the online library used by members of the large yahoo chelation groups you'll see this feature. http://livingnetwork.co.za/chelationnetwork/hairtest/hairtest3/
Both Andrew Cutler and Boyd Haley write that Hg has a terrible impact on adrenals and related stress response hormones.
In the large yahoo groups we find that members do well when they start to address adrenals and thyroid before they start to chelate, but know they won't resolve the problems without chelation. Remember that Hg fouls up thyroid too, including TSH levels. Therefore you test results might come back looking just low normal even though you have symptoms. I have to use thyroid supplements because my test results always come back negative. Cutler has tips for selecting certain thyroid tests that give you a better chance of getting a more accurate feel for the state of thyroid.