Hi Wells...what red said...
I think you've probably still been waiting for her, not really and truly moving on.
Regarding the new relationship, she has a chance to look shiny and new for someone who doesn't know all of her faults yet. For an unrecovered A, it's so much nicer to build a shiny new life and gloss over the past than to honestly do the work. That's her choice.
Once you're able to let go of her choices and really acknowledge that she isn't good for you, you'll be able to finish healing. I wonder, if she broke up with him tomorrow, came to you and said she quit drinking and wanted you back, would you be sucked back in...and end up watching her, and making "rules", and worrying...
I think it might be time to rip that band-aid off...