Becky,
Everyone has a resposibility to themselves, to live their own lives, and to make their own choices, good or bad. You could not have done anything to stop your mother's drinking if she wasn't ready to stop. Her drinking and her death was not your fault. You have nothing to feel guilty about.
My prayers go out to you. I'm glad you found us and I hope you keep coming back.
Hugs,
JG