Have you had counseling for yourself, pappillon? You haven't mentioned it here. If not, is there a reason you haven't sought out a therapist?
You are unfortunately still, after all this time, extremely vulnerable to your addict husband's control of your thinking. And without help, you will continue to be. It is very difficult to maintain good mental health when an addict with an agenda is working on our psyche, pressuring us to feel sympathy for him, deflecting blame on us for the problems his refusal to get clean caused, using our children as emotional blackmail, pretending to be a moral person when he lies and abuses his responsibilities as an adult and a parent, abandons the marriage, and, from a distance, continues to create crisis and trauma in those family members who are suffering because HE LOVES DRUGS.
A good counselor can give you some objectivity about this mind-f*** you have been a part of. You can learn to value yourself and trust your decisions better. You can stop taking on unearned guilt. Life with an addict messes us up. And we rarely get better without outside help.
I truly hope you will find a very good counselor and stick with weekly counseling for a minimum of one year. As is written in Al-Anon literature: "our thinking becomes distorted." And the tragedy, in my opinion, is that the addict has such mental power over his loved ones, that he actually causes them to believe that they--not he--are the failures.