Hello Erin,
I think grief is to be expected - for what was good and for the lost potential in your relationship as well as him as a human. I don't see you slipping into self pity or rewriting his addiction past.
Do you attend local Al Anon? I personally would like to know you have wise and empathetic face to face support. Do you go to a counselor? There are some who work in grief counseling and perhaps that would reassure you.
Peace,