Yes, I played the role of mother and my husband played the role of child. Well, unruly teenager would probably describe it better. And the more I treated him like a child, the more he behaved like one. Like Shellcrusher, I didn't really recognize it until I got into therapy.
I second the suggestion to read Codependent No More. Also, if you do consider therapy, make sure you find a therapist who has experience with addiction/codependence.
L