The first priority is to get your fluid intake up to spec, then you increase the protein over a period of time as your body will allow. Your pouch capacity is reduced right now by post-op swelling. That'll go down as it heals, increasing the amount of food you can take in at a sitting.
You need to be aware of your protein intake, and be working towards satisfying it, but don't panic if it takes a few weeks to get there.
While you're working on it, do a search in the archives for "hair loss". That's next!
CT