As clich’ as it sounds, time mends all things, including a broken heart. Even though it hurts within every fiber of your being, just hang in there. Try not to listen to sad music or movies, torturing yourself doesn’t help anything. Do activities that you enjoy such as playing video games, or drawing, or painting, or swimming, do things that keep you busy. The busier you are, the less time you have to dwell on what happened to make you feel this way. Eventually, the feelings go away on their own, and stop returning.