Getting sore after a workout is not good. What if you get in a fight that day? If you're sore, you won't be in optimal condition.
As for the water, bodybuilders drink a gallon or so per day. If you're drinking this much, or even almost this much, you don't have anything to worry about. If you're not drinking this much, and desire to do so, build up to it SLOWLY. Otherwise you will be peeing every 5 minutes. But, even half a gallon is sufficient. (the 8 glasses that is recommended by doctors or whatever is half a gallon, for reference.)
For protein, for building muscle, 1g per pound of bodyweight per day is plenty. So if you're getting this much, you're fine.
You could just be over doing it. How long are your classes? How long do you train for? Maybe you need to reduce it a bit and build back up.
Just suggestions.
IronFist
"If you like metal you're my friend" -- Manowar
"I am the cosmic storms, I am the tiny worms" -- Dimmu Borgir
<BombScare> i beat the internet
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