I have worked with DV families and currently work with kids 0-5 who have special needs..many are drug exposed, from chaotic homes, etc.All I can say is KUDOS to you for getting them to therapy..you've been sick (I am a fellow codie) and in OUR sickness although we love and take care of people, our obsession with the addict can leave our kids feeling neglected and anxious.
But you are taking care of this..getting them the help they need..hopw great for them that you are willing to acknowledge what is happening and are willing to take action..so many kids I see don't have that.This can be worked through, a stable environment, the counseling for everybody..you can turn this around and you are being a really good parent.They need you, and the guilt is just another thing that can get in the way of moving forward..please let it go..there isn't a mom out there doesn't wish for some kind of do over..keep up your positive parenting..big hugs from another mom..