We create our own stress. Exchange your expectations with appreciation and enjoy life's little moments. Don't spend too much time stressing over things that you have no control over. When something doesn't go as you expected it go take 90 seconds to freak out, then let it go.
Problems are easier to solve when you're not in a stressed out state. You may think you do better in a stressed state but that's just a lie that you talked yourself into believing. Why do you think football players,basketball players etc.. talk smack to the opposing players? They do it to stress the opposing players out to the point that they are off their game. When you are calm you see things more clearly.