Breaking the cycle of emotional violence

I had a family member who was and is emotionally violent towards me.
I find it very difficult when things get very heated to NOT be emotionally violent in return.
What is the best way to break this emotional violence cycle?
I am a parent, now. I have worked very diligently in breaking the cycle.
I have never been emotionally violent towards my child. However, I just got off the phone with a customer service representative who I was, possibly, a little emotionally violent (oops!!).
Working at being harmonious, universally.