I'm not the dietician, Sunny, but I remember posting something similar in the early days of my being on the plan. That was back on July 3rd. To me, in my humble and admittedly newbie experience, you need to add more calories and fat, and try to follow the menu plans as closely as possible. It seems to me that Alli really works best when you plan out your meals and snacks in advance and stick to it.
I used to be a chocoholic and I would crave sugar like nobody's business but I quickly lost the cravings when I was following the plan. My best friend is the nutritional log, which not only calculates your calories/fat intake, but allows you to put in your own favorite brands of foods and create your own menus. It got to the point that I couldn't eat everything on my plate for a while -- it was too much! But once I adjusted, I was never hungry again and I've lost all those cravings. Now I'm just as happy with an apple and peanut butter as I used to be with chocolate.
By playing with the nutritional log you can spread your snack calories out and schedule one for 8 p.m. I have the same need to eat in the evenings, and before bed I usually have cereal and soy milk with fruit or almonds. I am losing about 2 pounds a week and am quite happy with that result. Of course, each one of us is diffent and all I'm doing is trying to encourage you and congratulate you for making the decision to change your lifestyle to a more healthy way.
As to the water --- how about trying to carry a water bottle and take sips often through the day?
SD 7/3/08 SW 202 CW 176 HT 5'3" GW 150