Most Helpful Guy
Leave quick, don't give details on where you are going, end communication with him, never respond to his attempts at communication. These types usually turn violent when they can no longer control someone.
Also if you can, make a point of documenting his abusive nature; have a recording device on when he is around and a cel phone with someone you can speed dial for back up or keep a friend on the line on the phone if he comes near you especially after breakup.
I like another poster's idea about having backup.
Read a book called "The Gift of Fear" by Gavin DeBecker to get a look into the minds of these types of people and how to deal with them.
Most Helpful Girl
Yesterday I had just advised a girl in a bad situation who was with this schmo for 5 years. I told her to get out, lock, stock and barrel, and with everything I had went into deep detail with her about, she is definitely----Hitting the road, jack. It took her many years to Finally see he would never change, nor would anything ever get better.
When Anyone is in this abusive, or even abusive and physical nowhere Relationship, it's time to take the bull by the horns and start thinking of yourself. Unless they are willing to get help with You in communicating and compromising, it is never going to be any different, just seeing things their way, or it's the Highway.
Taking a break from one another is also the way to Begin your Beguine. If you don't want to just give him his walking papers right off the bat, then take a long recess from one another so you Both can do some serious soul searching. See how that goes first. Many couples do this first before putting the horse before the cart.
But more than likely, even if you were to dangle a carrot over the ol' horsie's nose, he will still be standing in the stance, never Willing to dance.
Good luck. xx