I think we are all struggling a wee bit after the over indulgences over the festive period! Think of all the goodies your body has got used to over the past few weeks! Chocolate, wine, Christmas cake etc etc ( jeez I'm suddenly hungry). From the reading I've done it may take us a wee while longer to get to ketosis because we have excess glycogen stores to burn (I think). They do also suggest cutting down on carbs for a few weeks before starting to reduce side effects - not likely over Xmas! After the headaches I've suffered I would urge those considering starting or awaiting packs to cut down on carbs and alcohol before starting! If anything a few pounds could be lost before Exante!
Good luck! It will get better - I'm day 4 and definitely feeling MUCH better today, more full of life and I have a metallic taste in my mouth.