Did you do a parasite cleanse first and continue parasite cleansing before and after the flush?
People usually get sick from Liver Flushing when they neglect the parasite cleanse. As well, when you dump a lot of toxins, sometimes you DO feel sick. My best flush when flush #10 when I vomited several times the day after the flush (I've never vomited on any flush before or after that one). If that was my first flush I might have thought it was "bad" when in reality it was one of the best.
Anyway, it's something to think about. I think Liver Flushing is really important.