SOme people get them because of the carb withdrawl or sugar withdrawl...my DH was cafeenie withdrawl...it is alot to take away from a body at once...and people are bound to feel it. Hang in there, you can do it. It lasts for only a few days, and then you start feeling better. Just think, that soon, your body will be feeling better, working better, and burning those calories and fat better.
Hugs