Argument Turned Into Domestic Violence

Hi. My husband and I got into a huge argument which turned into hard domestice violence from both of us. He hit me over the head with a bottle and coffee table. I too hit him back. I was cut on the head. He has not been in trouble for the last fourteen years but he went to see the Corrections Department in Rotorua Nz and could only tell him he was looking at 2/5 years. I recently wrote a letter to his Lawyer and advised that I would go through Counselling Anger Management Courses with him We have been married for 13 years. He also assaulted my cousin on the same night as she was trying to attack him to leave me alone.
I do not condone his behaviour but he and I are willing to help each other with courses.
What can i do

there's no one here from New Zealand, but I do suggest you get an attorney's advice locally.

Honestly based on this and your other posting, do you really think this is a healthy relationship? You both need help separately and then possibly together. But helping him "out" won't solve any of your issues.