If you feel the way you did you should have stopped the fast at the fist sign of not feeling right. Always listen to your body. That's the way it talks to you.
You're better off doing one or two day fasts multiple times until your body gets accostomed to going without food. Once you get to that point, you can add a day.
Also I have to tell you something that you and all the other people hate to hear that fasting is not the way to lose weight. Well you will lose weight during the fast, but because you will have slowed your metabolism down by fasting, when you start eating all the weight will return plus some extra.
It's in what you eat, and the reason you are eating to begin with. Eat to live like animals do instead of living to eat.