Dealing with a Narcissistic Family Member

How do you deal with a narcissistic family member that seemed to you always had your back growing up but only did anything for you for their benefit but you can’t seem to distance yourself from them bc they are actually your mom. But they are the one who knew and protected your abuser growing up? Abused drugs and you had to raise your sister. Did all of these horrible things but she has drilled into your head so far that she is the only one that will ever actually be in your corner no matter what. And it’s affecting your marriage, you as a parent, as a friend, and your everyday life. But you can’t seem to distance yourself bc you feel like that you will be hurting your child in the long run bc if you distance yourself from your mom then no one in the family will have anything to do with you including your dad and sisters so you won’t be able to talk or see your nieces or nephews. The only two people in the family that have your back are your uncle which is your moms brother and his wife my aunt. I’m at A loss so any help or guidance or advice would help! Oh and she’s drove you to the point several times in your life to wanting to end your life.