Take breaks to unwind: Even if you only have five minutes, take a moment to breathe and walk around the library; find a friend to talk to or go to the Pit for food. Frequent short breaks will not only help you feel better, but it will make you more productive in the long run.
Schedule time to relax: I find that giving myself 15 minutes before bed to listen to music and unwind helps me fall asleep after studying. If I do work right before I go to bed, my mind is often still racing with test material when my head hits the pillow.
Exercise: A quick trip to the gym, or a workout in your room, will relieve stress and release endorphins, helping you stay focused throughout the week.
Find your study spot: Sometimes, the library can be overwhelming particularly during finals, when everyone is rushing to find a spot. Take this time to try out other study spots around campus where stress doesn’t permeate the air. The main lobby of the gym has nice tables and is surprisingly quiet. Also, several academic buildings have rooms open for studying on the weekends and at night.
Remember to keep everything in perspective. Your mental and physical health are as important as your grades. Good luck & happy studying!