golden cirlce are fine, i find them way too sweet so i dilute using mineral water. however, don't use them as a subsitute for water. if you haven't lost any weight yet, then aviad everything but clean food for the 2 week induction. it is to kick start the loss so it's best to be as clean as you can.

yes to the second question about feeling crap, it is likely caffeine withdrawal and part of the deal when your body switches over to ketosis. drink LOTS of water, i cannot stress this enough. try for 3 litres a day.