First I am sorry for your loss. I know you are very emotional right now.
But since you wanted advice, here goes.
Your mother was an adult, she chose not to take care of herself. It was not your job to parent your parent. Please re-read your original post. All of the things your mom had done in the past, now that she has passed, you have justified away in some way. That is from grief. It is normal to grieve and want to have happy memories of lost loved ones. But people are human and they make mistakes and they hurt us. It sounds as though your mom was a troubled woman and that many of you suffered for it.
Don't take it out on your husband. It sounds as though he saw her flaws very clearly and felt that he need to defend you against her behavior. Blaming your husband will not make the situation with your mother better. Please make no rash decisions. Grief gives people ALOT of anger and it sounds as though you are turning the anger on the person closest to you --your husband. Even though really, you are mad at your mom.