Before sleeping, think about what makes you sad the entire day and tackle it. If you can't think why you're sad, then change your lifestyle. Surround yourself with people, good people, enforce yourself to do things you like. It's okay to be sad and cry, but it's not okay to be depressed. Forget what disturbs you and try to come up with solutions to solve it. Pain is inevitable, but suffering is a choice. Don't allow yourself to be in misery.