Drug addict mother at my wedding.

Kaily
My mother has been addicted to prescription pain pills for about 10 years now. She has used everyone in my family as a scapegoat. She has been "trying" to get sober for about two years now. I use trying lightly because most of my family agrees that she is doing it for attention, not to actually get clean.
When she is high she acts like a child and throws tantrums if she doesn't get her way. She is a slurring and blabbering mess. And if she sits down for five minutes she falls asleep, dinner table, drivers seat, you name it she will be asleep. It has gotten to the point that I don't want her at my wedding if she continues on the road she is on. Does anyone have any advice to give on something like this? I'm really kind of stuck on how I'm going to have this conversation.