In my opinion there is no difference in a user and an addict.. Both are abusing a substance...but in reference to your question your BF sounds like a full blown addict in active addiction and a dangerous addict at that...
What really concerns me is this violence that you speak about.. Why are you still with this guy if he is laying his hands on you??? Addict or no addict, there is no excuse for violence.. Get out now before something tragic happens