In my case, after each flush I usually feel very energetic. I don´t know what protocol you are usuing to do your LF, I do it very simple, by taking one dose of Epsom Salt and after 2 hours i take the combo( 170ml OO (Olive-Oil) + 170 ml Lemon juice) and that is all, no more Epsom Salts .
The following day I only eat cooked vegetables, but in the evening I go back to my normal diet.
Good luck.
Fernando