I'm not the expert but I suspect that you're body's trying to detox without the outlet to do so, so it's staying with you! You really should do Master-Cleanse by the letter. For the SWF, it was difficult for me as it is for many. It became infinitely better for me once I started doing this:
Cut one of your lemons in half and have it handy.
Chug as much of the SWF (Salt-Water-Flush) you can at a time.
Take a BIG LICK of that lemon. Cover your whole tongue. It takes away the nasty taste and somehow stops the immediate upchuck reflex.
Sometimes my tummy would still feel a little queasy but that was the worst of it whereas without this technique it was a long process to dring and laborous to keep it from coming back up! This made it so much better. Good luck!