Once something is done it is what it is. It can't be undone. All you can do now is damage control. It is a lot easier to step back from the situation and thinks about how you should react to prevent the damage in the first place. If you can control yourself long enough to think about it you will give yourself time to realize that your first reaction would have done damage. Take a step back because you will make the best decision on how to react after you think about what your actions would bring.