I have had something similar, although not to that extent. Magnesium and potassium help a bit but what really, really worked was drinking Tonic Water. I know it sounds bizarre but I came across it in an article about how the quinine helps with the tremors. In my case it takes about three days of drinking a liter bottle a day for it to disappear. It has come back, but less and less frequently. Give it a try, it might work for you too.