To calm yourself down, first you need to sit in a comfortable posture and position, which will help you to relax and more grounded. After this, take a deep breath and start meditating, while making sure that you are in touch with all your breath's movement. As you try to come in touch with your breath make sure that you shake or shrug your shoulders and any body parts to release tension. Additionally, always try to stay positive and avoid thinking of anything, which stresses your mind and life. To learn more about this, you can visit http://www.wikihow.com/Calm-Down.