I am truly sorry for the situation you find yourself in; being the child of an individual unable to tear themselves away from substance abuse is a terrible existence.
Although I am not licensed in Minnesota, it is probable that from a legal perspective, there is little you can do, your mom is on a path that will take a lot to divert her from, in a time frame that might be measured in years. My best advice is for you to take care of yourself, do you have a plan? Where will you go if your mother continues to deteriorate and how can you protect yourself from her problem? Seeing a local attorney with experience in these issues is probably the place to start. If you are unable to afford an attorney, there are some excellent clinics available through the Law Schools in your area.
On a more personal level, you should visit Al-anon and Al-ateen, these organizations can help you deal with the issues you face by letting you talk to people who are in similar circumstances.
I am licensed in New Mexco and Pennsylvania, and therefore any discussion of issues related to other states must considered within that context. In addition, my comments are not intended to create a legal representation but merely to respond to the limited facts presented in the question. A more complete legal areview can be obtained through local counsel.