There are no such things as correct or wrong emotions... The only thing that is correct or wrong is how we act on our emotions. There is nothing wrong with getting angry at situations or people. Just try to act on the emotion in a constructful way. Instead of yelling at them try to explain to them that you get a little anoyed when they do what ever it was that they did that made you angry. If you do this in a cool collected manner than the other person will most likely also respond in a positive manner...

Hope this helps some,
Jason