Muscle weakness

That was my first thought on reading your first post - likely potassium as our post-op diets are short on it (particularly the carb counting diets) and the normal supplements don't cover it to any useful degree. Usually we have enough reserves that it doesn't show this quickly, but if you were marginal to begin with it's quite possible. Low sodium V8 juice is about the best non-Rx supplement that i have found for it.