Too bad you went to the "Juice" so early...
I too started a fast last Sunday. , I have been fasting off and on for about five years.
I originally wanted to fast for weight loss, but quickly realized that that was just a bonus.
I fast now for the health benefits and the natural, high that I get while I am fasting.
On or about the third day of your fast, your body switches gears and starts burning fat for fuel, like a hybrid car when it goes from gas to electricity. The difference is obviously more complex than that, but your body was just trying to switch fuel sources. If you can get thru that time when you think you have to have juice, you will quickly settle into a state of mind that is hard for me to explain but it makes me smile. I am in a state where I know that I am in control of my body, and my mind.. well, my body anyways.
My longest H2O only fast was 40 days, that I did a couple of years ago... This time I will just go until I get that undeniable hunger that tells me it is time to re-feed.
If your goal is to loss weight, well there are many ways to do that, one of which is a juice fast, though that is not really a fast... A "fast" is always, just water.
If you ever do get past the third day in a fast, you will quickly understand what I have been rambling about