"Nice guy syndrome"? I'm familiar with that. I like to call it the, "Kick Me" syndrome. Actually, check out this site and see if you can relate:
http://www.codependents.org/patterns.php
If you think you're codependent, than she's playing you like a fiddle. Not to worry, my AH has played similar games with me. That was until I figured out that I am a textbook codie a few months ago.
We had a little chat. I told him exactly what I think of him when he's drinking, told him how I had prepared myself for a divorce, and told him my life plan for the next year and told him my boundaries. He was silent while I spoke. Was nice. I had been holding it back for so many years because I was afraid of his reaction. Man did it feel good to get his attention.
I feel so much better about myself. He may not be able to hang on to his sobriety, but now I know I can leave.