Hi Rollercoaster!
My sister is a heroin addict. (So is my cousin.) Your name certainly rings a bell. Feel free to pull up my threads, I share a lot about the current dynamic of her using, stealing from me, my mother enabling her heavily and trying to throw her guilt onto me. My phone calls were going exactly how you explained, on the phone with one after another, sister, mom, everyone upset, no progress made EVER.
I finally had to set some boundaries. I moved out of state years ago after my sister stole a good deal of my belongings, so that helped a lot to create some distance, literally and figuratively. More recently I've started applying boundaries to my interactions with my mother as well. I'm not no contact with either of them, but my contact is quite guarded. I don't talk to my sister a lot because I won't support her drug use - I won't buy her anything, I won't giver her money, I won't give her a place to stay, and I won't try to get her a job. Those are all things she can do on her own. I also won't get sucked into every latest dramatic story of terminally bad luck she brings, I'm not the one who can solve her problems. Because I won't do these things, she doesn't contact me nearly as often as she once did.
With my mother, I have made a conscious effort to stop engaging in discussions about my sister. It hurts my feelings, and it makes me angry, so I have to stop doing it. Period. It also does absolutely nothing to improve the situation, so there really is no reason to do it besides the draw of enmeshed drama that I recognize I have some sort of sick weakness for.
I will say this: Just one day, one single day, I wish people would get as stupidly excited for me to do basic crap like brush my teeth (and floss!), or go to the DMV, or send in the phone bill, or any number of daily tasks that *everyone else on the planet* does. See, because when my sister does these things, you would think she was an Olympian the way they throw on the extravagant accolades. "What's that, mom? Sister went to the grocery store?! Call the President, he'll want to know about this!!"
I know it's not funny, but if I can't laugh at everything sometimes I think I would go completely insane. I'm sorry for the reasons you find yourself here, but welcome to the forum!
