First of all, be realistic and stop blaming yourself and thinking you're a bad girlfriend, you (subconsciously) add fuel to the fire and allow, accept and support arguing. You don't have COMPLETE control over the arguing, but you could say "Let's sit down (over a cup of coffee) and talk about this reasonably". The world does not revolve around you. Bad things happen without you causing them. There is tension in the household, but, you only ADD to it (unintentionally and subconsciously), you don't CAUSE it. Maybe you really don't know what an addiction is and how much of a trap it is for the other person. Yes, he is a VICTIM of his addiction, but, he is also the PERPETRATOR and, ultimately, the CAUSE, not you. You and the household are suffering from his addiction (He has the addiction, you have the affliction), but it sounds like both of you want to work things out. The first thing an addiction does is RAISE "the threshold of excitement" (the senses need more stimulation that can only be satisfied a certain way). That's what a "FIX" is (satisfaction). When you say "Let's SIT DOWN and talk about this reasonably", have the coffee pot and cups ready and be enough of an example to him that he will ALSO want to be cool, calm, collected, and commited to the conversation as you are. If you "set the scene" well, it won't be a substitute for a FIX, but it will probably be enough of a distraction to allow him time to be "FULLY" reasonable. Progress will not happen overnight, but it's a start. Maybe you can go with him to a Narcotics Anonymous meeting.