Hi (((StopInsanity))) and welcome!
When we made our son leave 5 years ago, we took his keys. Changing the locks would serve the same purpose. I also learned that as long as I tolerated disrespectful behavior (and I did), my sons would continue to treat me that way. It took a loooonnnnnngggggg time, but I started putting boundaries in place. If there was cursing or the blame game, I cut the conversation short. As I changed, so did our relationship, for the better.
I would encourage you to read the stickies at the top of this forum and also check out the naranon forum. There are a lot of moms there who are also dealing with an addicted child.
hugs ~
deedee