Hello Susanka!

I'm on the 5th week of Atkins and have had periods of nausea too, over time. It seems to help me to brew/boil some tea out of fresh thinly sliced ginger. Maybe worth a try? Generally, diarrhea, cramps and nausea is a dead giveaway of dehydration/water intoxication (different stages of the same thing, basically), i.e. too few electrolytes in your system. Do you take potassium/cal/mag/zink supplements? If not, try to get some asap.

Best of luck! I hope it'll turn out alright in the end.