oh, you did all the right things! What a good post for people to read, and see the whole thread. I was going to mention Epsom Salts . And cutting down on water--Definitely, one thing we tend to do is drink too much water--Often using it almost as a way to 'fill up'. The sensations in the empty digestive tract can be so odd--when you reflect on it, we are almost always cramming something down, esp. if we eat three times a day, normally, and the Water Fast is a rather unique physical event.
Another thing I often mention to people, is to learn EFT. It's a form of non-invasive meridian balancing, and it's the little blocks in the enregy meridians --that all connect to organs and processes and emotions-- that can cause trouble and strife. EFT is free to learn, to order the manual online. It really helps with riding out and *over* the changing symptoms. I forgot about that, even though I often use it; it's almost second nature now.
My suggestion is to learn it before (or after) a water fast, and use if for everything--but it's really good for getting through the rough patches, and quickly!
It may well have been that you were drinking too much water. Water only "according to thirst" is the old Water Fasting dictum.