On the drinking water, drink when you are thirsty. Drink when you think you might be thirsty, but don't set a limit. Drinking too much for you is bad.
The old ten (or 8 or whatever) glasses a day is a misquote. The study they took that from found the body needs to consume that amount of water per day, but a significant part of your body's water actually comes from food. A later study has found that by the time the body has any real noticeable lack of water the person is already thirsty.
So setting a limit of so many ounces of water a day can be bad. But make sure you drink when you are thirsty. (does that make sense?)
My advice? Hit the gym. Do rowing sprints. Row 200 metres in less than 45 seconds (the time per 500m should not go above 1:50). Then rest for 45 seconds. Then row again. Aim to do 10 of these. You'll soon see a difference (and it is a fantastic low-impact cardio workout). you can program this into rowing machines real easy.
If you can't get to the gym then do some sit-ups, crunches, press-ups and try to walk faster than you do normally. And watch the food. Skinless chicken breast is good as it has next to no fat and a good amount of protein (turkey breast is better). Substitute snack food (chocolate and crisps) for fruit.