I did not mean to imply you were starving yourself, just that even a little solid food changes the nature of a fast.
Try and drink water throughout the day. Small sips are much better than chugging a whole lot all at once. Make sure you are making plenty of urine to help pass toxins, but do not drink so much that you risk electrolyte imbalance. This can be very dangerous. If you experience any blackout or fainting spells you can try more water for a day or two, but it may be necessary to stop fasting if you cannot recover. The symptoms may last only a day or two or can go on a lot longer if you are real toxic. Withdrawal from caffeine and Sugar can also cause headaches and weakness.
My longest water only fast was just nine days, I wanted to do twelve days, but my doctor made me quit. Since then I prefer juice or green-drink fasts with an occasional day of water fasting.