I also experienced this, I was great up until the 3rd flush, and then anxiety and emotions I hadn't felt for years hit me! I believe its just the way of the body getting rid of the emotions that are stored inside, I have now done my 4th flush and the anxiety is better, still there slightly though! I am doing a kidney cleanse now as this should help with fear and anxiety.
The key is to keep flushing, to get rid of all old emotions unfortunately this may mean experiencing them again, I am looking forward to having a clear mind :)