When things are going badly, remind yourself that bad times don't last. Balance negative thoughts with a list of what's going right in your life. When you think everything is wrong, try to take a realistic look at where you are. Things usually aren't as dire as pessimists make them out to be. Focus on what you can control and try to change it.
Many pessimists worry all the time about what's going wrong.
Think of worrying as squandered energy and try to focus on the positive.