Welcome, I am truly sorry for the reasons you have come here. I'm sure you know there are no fast answers to the questions you asked. Please also know that all of us who love addicts have enabled because we thought we were loving them, supporting them, helping them. It doesn't make us bad people...just people who did not know better as you have said. Now we do know better and we try to work our own recoveyr each day. It can be a slow process, but so rewarding.
I'm so sorry you feel lost and alone. We all reached a point where we could not take our pain any longer and we were lead here. I'm glad you are here too. Please read all you can, share and learn...it is so helpful. I found Naranon meetings and the face to face support to be a life saver as well. I've learned tools to use to handle the results of addiction in my life and little by little i started to feel so much better. You can too! Hugs and prayers for you and your children.