Candida, and even treating candida can cause this. You liver may be overloaded. You could try backing off on your supps - eliminating detox supps did this for me, and actually helped my body expel candida better because it was not so busy dealing with all the supps. Also, the by-product of candida, acetyladehyde (sp?) can cause you to feel this way. If you take some alka seltzer (which neutralizes the acids that detoxing releases) you might feel better. Also, are you doing anything to actively alkalize? Like taking minerals?