Welcome,
Do you get enough sodium along with the mag and potassium?
Enough is quite a bit when on a strict Keto Diet.
There is a long thread on it here: http://forum.lowcarber.org/showthread.php?t=445775
And you require enough water to stay well-hydrated, dehydration is another issue with any LC Diet.

I don’t know of a book with the title as you wrote it on your profile. Are you keeping total carbs below 20g? With protein moderate and fat to satiety? You have found a great forum, look around. All the best,