You turn minor matters into major concerns. You have difficulty sleeping. You have physical problems, such as headaches, backaches or upset stomach. Don't get overwhelmed by too many external demands. Try to get an adequate amount of rest.
Sleep deprivation can contribute significantly to high stress levels.
Practice deep, slow regular breathing from the abdomen. Do this for 10 or 20 minutes alone in your room, or even for a moment or two in a classroom. Eat healthy, well-balanced meals. Eating too much or too little can contribute to stress. Regular exercise provides the physical release that restores your body to a relaxed state.