Mercury poisoning typically affects the adrenals and thyroid function so having cold extremeties reflects this.
Since you had quite a few Amalgams you shouldnt expect immediate results (although possible) from chelation protocol.
It is important to chelate at your systems speed which is dependant on how well your pathways of elimination are operating (liver bowels kidneys etc), or else your symptoms may increase in intensity.
You should also make sure you attend other dental issues like root canals and crowns if you have them as these can have a greater impact on your immune system
Mike