I am also going through the same experience now. and it hurts so much when you are not receiving the necessary support. friends are accusing me of being "unfilial" so i have decided to stop talking and be selective with the people you talk too.
nevertheless, i found these helpful reading resources
Narcissistic Abuse: How Do You Grieve the Death of a Narcissistic Personality Disordered Mother?
How survivors deal with the death of a toxic person - CNN.com
Hoping that i can one day heal and emerge stronger from the hurts of an abusive mother.