Hey kate
I largely come from the other side of the fence as I am a recovering alcoholic and addict. I am in a similar boat to you in terms of having a family member in that situation who simply will not gave up to their issues and bled everyone dry. The result was it made me incredibly ill and they carried on regardless.
What I learned is that just as the addict powerless over their using or drinking, I’m powerless over their behaviour too. I had to gradually step away and start to accept that unless they want to change there is absolutely nothing I can do. That doesn’t mean I don’t care – it just means that I cant rescue them – it’s fantasy.
From the addicts ppint if view, when I’m using I don’t care about anyone or anything – it all goes out the window