I guess you’ve been on the diet for at least eight weeks now, correct? I would think you were far enough along not to let the bitters bother you, but perhaps not quite. If something in the grape bitters is bothering you, it’s probably the alcohol. You can try not taking any more of the bitters, and see if you see a difference by the end of the day on Saturday or Sunday.
Is this the first time in a while that you felt as though you’re going backwards with the symptoms?
Enjoy the weekend.