You are getting divorced, it is not the end of the world. If he ever gets himself back together, you can, if you want to, re-explore the relationship.
For now, I agree with the others, no contact. You are not doing anything positive for you by keeping the lines of communication open. He left you when he became addicted, now it's time for you to move forward, let go.
I wish you the best, life is a song worth singing, sing it!