Shakiness can be a sign of weak adrenals, which are often affected by mercury poisoning. Weak adrenals don't produce enough cortisol, which regulates blood sugar, and so many mercury toxic people are hypoglycaemic. I certainly am. I leave no more than 4 hours inbetween meals, eat protein with every meal, and take chromium picolinate after eating. If I don't eat frequently enough, I get shakey, anxious and very tired. Then I crash. Have a look at Andy Cutler's recommendations for hypoadrenalism / hypoglycaemia. It might help to take some adrenal support.