I’m in disbelief reading your story. You have been through so much and had to witness the horrific change of drugs on family, including your own children. It seems you need a support network, and The Icarus Trust can do that for you. Everyone is trained (and it’s free, and they are here to help you), and can “signpost” you to the right sort of help. You can contact them on info@icarustrust.org or on their website http://www.incarustrust.org.
I wish you all the best and that everyone pulls through!