I do a lot of work with people who have anger management problems. Either they express anger too aggressively (sometimes resulting in violence); or they don't express it enough (sometimes resulting in depression). You can fix that (see my posting of 9/14/07, Anger Management). I'm concerned here with people who just seem angry at the world, and don't realize it's a problem. This can be the result of too much stress for too long. And/or depression. Maybe a sad, frustrating life. Sometimes having experienced a lot of hurt. Often they are alone, because people don't enjoy being around them. Take a real look at how you relate to people. Do they disappoint you too much? Could YOU be described as "mean" sometimes? Start today being nicer to people. You will be happier (and what have you got to lose?).
Anger is a normal emotion. Express it in a healthy way. It's best to respond to situations that trigger your anger when it happens (if possible). [REMINDER: Yelling, and demeaning the person is not a healthy way of expressing your frustration.] Then move on. Get over it! Use your anger to accomplish something productive, for example get motivated to resolve a relationship problem or fix a work situation, improve your performance (as in a game or sport).
Don't be a hater!