This is a very big and very common problem which people have to face within the relationship or within the family. Myself I have experienced it with my father who was addicted to alcohol and although this was not a pleasant experience I have learned a lot from it.
Now... one of the things that I have learned from it. Addiction can be stopped in the moment and it has been proven many times not only by me but also by others. But before everybody who is addicted, understands it and applies it in their life, it may take many, many years if not decades to get to this point. And on the way towards this point of understanding it there is a certain pattern which repeats itself very often among the addicts and their families. I have seen it with my father and later also with many other people. Recently I have heard it from my friend who's boyfriend is using drugs.
Thus the point that repeats itself among these people is that they are aggressive and abusive towards their family either by using abusive words with screaming or even using physical force. There are different reasons why they behave in this way but in any case there is never a justifiable excuse to do it.
Anyway how do I deal with it ? First of all it is always important to remember to bring it all back to yourself. Look inside of you whether you are creating it for yourself because you have a victim syndrome and in this case you are in this situation for a reason and you are simply co-creating this experience for yourself and as long as you don't apply the correction within yourself you will recreate this type of experiences in your life time after time.
But if you are clear on it you have to be careful not to make mistake by insisting and pressing your partner so that he accepts your help. In this case you may have a syndrome of the savior and again you are creating this whole experience yourself because you get some kind of energetic high from it.
Apart from this there is one more point to remember. You will never be able to help the addicted person to stop their addiction. You may assist them but it is impossible to do it for them. The chip is in their head and only they can stop their addiction thus if you insist and push them too much they may turn against you and attack you. Thus if you live with a partner with addiction then be the living example for them so that they may learn from you and be ready to assist them whenever they'll ask you for help. But as I said before don't do it for them and don't push them. They must do it themselves. This whole process may take a lot of time and it will require a lot of patience from you but if you really love them as you say, then this should be not a problem.
To be continued...