I had to call Children's Services when my son and his then GF both relapsed on meth and their lives were spiraling out of control. I knew that doing so might mean that I never saw my granddaughter again, and I haven't, but I was allowed the knowledge (from CS) that she was safe in a safe environment and well removed from the home filled with addiction. Knowing she was safe and well taken care of was all I cared about, and I don't regret doing this, even though it meant losing her. I had no rights, my son is my foster son and I fall into a whole different category than birth or adoptive grandparents.
Please do whatever you can to protect the children. We can't change the adult addicts but we can reach out for help for the children.
I will keep you and your children in my prayers each day.
God bless the child.