It is really important to keep a journal of what you are actually consuming. That way you can take it to your doc and say.. hey, look! I'm only eating 200 calories a day! Maybe you already are, but if you only have the info you just gave, it's not enough. Measure (weigh) everything, and write down what, how much, what time, how you felt... everything.
You should be pretty comfortable consuming at least 800 calories a day of food. It sounds like you might not be getting that much. This is something you should bring up with your surgeon, because strictures can happen, and it will make you unable to eat or drink enough. The idea of Water hurting for a day and a half.. this sounds all wrong to me. If I take too big a swallow, it'll hurt for a few seconds, or maybe a minute. Not a day!
