When things are really bad, and you are just not coping, how do you stop yourself taking out your anger on the children when it is taking over?

(Please note, I am reacting to 'disipline-needed' situations, not just random times when I get angry; and it is NOT physical, *just* yelling instead of talking calmly!!!).

* Walking away is not an option; usually I am disiplining my oldest who has many behavioural problems and constantly physically targets her little sister...or me...or uses objects as weapons or as ways to destroy the room she happens to be in at the time etc.