I am so sorry, it has to be very hard to deal with.
It sounds to me like you are putting some boundaries in place for yourself and that is good. Would she be willing to get any sort of recovery for herself? If not, there is absolutely nothing you can do.
I would just take it a day at a time. You said she will run out of assets in about a year. She will then be 81. She may be forced to sell her house due to needing more care. If that's the case you can cross that bridge when it comes.
Continue with Alanon and possibly consult w/an attorney to see what your options are in dealing w/her POA. I would also continue with what you are doing in just having minimal contact with her. I am so sorry, it has to be very painful since this is your mom.
These are just my opinions of course. It is like the air mask on the plane type of thing, you have to take care of you before you can help anyone else.