Take a deep breath! You will get this. You're only 9 days post-op. Getting in all the water AND all the protein at this point is hard. You and your new stomach have to get to know each other and that could take awhile. Don't stress too much, just focus on healing right now. Just keep sipping tha****er and eat what protein you can. You'll be fine if you don't get every single ounce of protein you think you're supposed to.
You're not failing! You're trying and you're learning how to live in this new situation. It will take awhile before you're healed enough to form the new healthy eating habits that you want. Don't try to force yourself into them, just do/eat/drink what you can, when you can. It will get easier!