Hi,
sorry you are feeling a bit bad, it can be part of the first week's difficulty. Some people have posted they have felt the same. Take it easy esp getting up, as rushing may make it worse. Take all the shakes you are meant to and drink the water. Try not to do anything too taxing, can be hard if you have others to mind or job etc., but be nice to yourself. If you have any queries ring your chemist, they should give you some helpful advice. I hope it passes soon, most on here said it only last for the first couple of days and then they have no more problems, hope it is the same for you.
Doirin