Work smart, not hard. Often when people say that they are studying 5 hours a day, those aren't 5 fully effective, completely focused hours of studying. Find the learning strategies that work best for you, find quiet spaces to really digest information, set up a review schedule that works throughout the semester and not just in the days before an exam, and you'll do just fine.
A professor of mine once put it best: if you're spending more than 3x as much time studying for an exam as you spent in the corresponding classes that are covered on said exam, you're doing it wrong.