While symptoms are typically exarcebated after mercury removal (due to a temporary mercury increase in the system) its important to know if all the mercury has been removed. Do you have crowns? Its possible that mercury fillings can be left out underneath these and chelating will make things worse as it keeps pulling the stationary mercury into the blood.
Also, and I don't know if chelation protocols adress this, its important to have other metals removed as well; metals like palladium and nickel are typically found in crowns; these should be removed prior to chelation because chelating agents can interact with these.
Of course, its critical to have your elimination pathways up to speed, special bowels and kidneys as to not reabsorb the toxins.
Also (and this is typically shadowed by the mercury dangers) root canals NEED to be addressed as they can be (and most often are) more dangerous then having amalgams.
Mike