I am sorry that you are in so much pain. My mother is the alcoholic in my life, she has been drinking non stop for 66 years, she gets hammered daily. She is mean, agressive and downright nasty.
This is a progressive disease that has no cure. Your mother will never again be the mother you fantasize her to be. Her mind is altered by alcohol abuse, yes, she can get better IF she gets sober, and works a strong recovery program for life, the chances of that happening are less than 10%, not good odds.
The bottom line is that you need to work on you, check out other meetings in your area, go back to therapy, these actions will help you to understand what you are dealing with. If the people in the meetings are older than you, so what, it's not a party...if you were working in the corporate enviornment, when attending meetings there are people of all age groups participating.
Your mother is an adult, she is making her own choices, you need to do the same, you cannot fix her, you can only fix you.
Read the stickeys at the top of this forum and all in the Family & Friends section of this board, read Codependent No More, and, keep posting.