Hi, Kim! I’m going to preface this with saying Nar-Anon or Smart F&F could be a good idea, and the stickies here might help, also. I’m no expert, so for sure, don’t be afraid to look at the more established information here!
Quick thought—Boundaries shouldn’t be able to fall on deaf ears because they are rules of engagement for you, not her. And it’s up to you to enforce them. An example might be: boundary=I don’t have conversations with people who are high/tweaking/drink. She can try to engage you when she’s under the influence, but you can say “love you, but you know that’s my boundary, so call me when you’re sober and we can talk.” And then you hang up/leave the room/etc. Obviously, that doesn’t have to be your boundary, boundaries are very personal and it’s about what works for you and not what other people think you ”should” do.
I’m sure you’ve heard a million times we can’t control or change other people’s behavior. But, we can let them see and experience the consequence of their actions. What good is it doing protecting her from the repercussions of her choices? Additionally, there’s a reason airlines tell us to put on our own oxygen masks before we help others. How much good are you to your sister if you don’t take care of yourself first? Feeling as wrecked and chaotic in life as you do right now, if it got worse and also started to bring down your family and your finances, could you be any help to her then? Or would you be too destroyed?