Drink warm water, rest and stay warm. Put your hand in warm water with epsom salt. You can even take Epsom Salt bath. It will give you all magnesium you need through your skin. Soak your hands twice a day in warm water with ES.
Don't give in. Only major signs like heart pounding for a day, vomiting for three days, extreme fainting spells, then you have to brake your fast with water and lemon juice .
I know you will go to 40 days easily. Don't do any strenuous work.