Welcome to SR. It has been a Godsend for me.
I also have been married 9 years with 2 children with similiar ages to you.
I also knew some drug abuse was going on but I had NO idea to what extent.
I was very angry, among other emotions. I am still in the middle of my mess figuring out who I am and what to do. One of the statements that has been the most helpful to me is to remember the three C's---I didn't cause it, I can't control it nor can I cure it.
Take care of yourself and the precious ones. We are all here for you. There are others on this site who are much further along on their path and I'm sure they will give you incredible advice. I just wanted to let you know that you are not alone.