Don't beat yourself up ! If the only healthy thing you were to do for yourself today was to drink 8 glasses of water, that's still a step in the right direction. Remember, you're trying to change habits learned over a life time. That's not going to happen overnight, a week, a month or even a year. Change takes time. Thus the need to be patient with yourself and your body.
One thing I would suggest is reading some of the articles on emotional eating and stress. I'm a firm believer that if a person could reduce their stress, they'd automatically reduce their waistline. So, if you know you're comfort eating because of any stress you're under, then you need to find ways to reduce your stress that don't involve food. And one simple thing you can do that WILL help you reduce your stress as well as give you one more healthy thing to do for the day would be to take a walk.
Walking is not only great cardiovascular exercise, it's a great way to reduce stress too. www.sparkpeople.com/resource/wellness_arti
One small change is all it takes to change your life. You have to believe that. For now, you might want to read this Spark article on other ways to reduce stress that don't involve food.