Hi idreamblue
Yes, you are completely in the right place and welcome to SR.
My FIL was an alcoholic (died this year), my husband is an alcoholic and so are both of his siblings. The worse one of all though is my MIL who is not an alcoholic but completely toxic, so I understand where you are coming from.
My AH and I haven't spoken to MIL for 20 years and boy is it peaceful without her! Not so easy for you as its your mother but you can definitely make things easy for yourself by setting boundaries. This can take some 'getting your head around' and a good place to start would be for you to go to Al-anon for yourself, to learn about the disease, who it effects, and what you can do to protect yourself. Its great that your dad has found sobriety and maintained and I am sorry that your mother was never able to recover herself.
I heard the other day that for every alcoholic there is generally about 7 other people who it effects. These days I do have some empathy for my MIL, living with an AH couldn't have been easy for her but both my AH and I have no desire to get involved with that personality again.
My psychotherapist once said that he dislikes it when we keep toxic people in our lives because they are 'family'. He said that we should seek out people who are loving, kind, caring, thoughtful, genuine, etc, etc. Why waste your life with people who aren't at least some of these things. I know this is a bit harsh but there is some truth in it and once you are able to set up some boundaries to protect yourself, you will feel much more powerful when dealing with your mum.