Keep at it! I have done six MC's of lengths varying from 10 days to 21 days, and by far the second Master-Cleanse was the most difficult. I think it is because the expectations are there whereas with the first MC, there was the great unknown and the nice surprises of no appetite after a few days, energy, etc. With the second Master-Cleanse I thought things would only be better and they really weren't. I found it a lot harder mentally to stay on vs. the first Master-Cleanse although the detox symptoms weren't nearly as bad.