Here is what is wrong: overly Vatas do terribly fasting

Reality check: some people react completely differently than you do to fasting, and further - there can be a reason for these people that is not "lack of preparation".

You can't even imagine this! I'm talking 24 hour keep-you-up-all-night hypoglycemia, stuff you can problably not even picture. A few days of fasting does this to me. Then I learned that people with an overly Vata body makeup are in this category, (Ayurveda healing medicine). - I then took the ayurvedic body make up test and yup, i'm nearly all Vata. Gosh, no wonder I cannot understand what you are talking about when people like you say "gee I fasted for three days and it wasn't that bad". That is another planet for what my experience was. Attempting to fast gave me more health problems long after it was over than I had before I tried it - weeks and weeks after it was over.
(AND THIS WAS DESPITE PREPARING WITH A HIGH VEGETABLE, PURE DIET FOR MONTHS IN ADVANCE!)

Ayurveda may hold that once a person brings their body away from being so overly Vata, then fasting can be done. Newsflash though, Vata people trying to bring their bodies away from being overly vata should NOT eat raw foods - completly opposite from all the raw juicing philosophies out there. For now, I'm not going near fasting.