I'm so sorry you are going through all of this.
I used while drove my kids around for years. I love my children and I never wanted to hurt them but I put them in danger so many times.
I was talking to a GAL (guardian ad litem/ie lawyer for children) and she said that she never doubted that her drug addicted parents love their children, but the number one thing in the situation is safety.
This could end up being a long trip, so I would recommend Al Anon or Nar Anon for you. I know Al Anon really helped my ex/kids Dad this time around. It took the end of the marriage for him to do it though.
My thoughts are with you and your kids.
Welcome to SR!