Jerect, I know it feels rather sad to get to this point, but I believe your post is filled with hope too. Realizing powerlessness can be empowering...it is another step in changing what we can change...ourselves. I'm also glad you were able to confide in your mil...keeping secrets is such a difficult thing. As I have let secrets go, I realize how unhealthy they were for me.
I'm not sure where to draw the line in being a good wife and enabling my AH to use drugs. I want to be there for him when he needs me but yet I don't want to cushen his fall either.
When I first started here, I remember reading that an easy way to start distinguishing between supporting and enabling was to not do anything for my addict that she was capable of doing herself. Another thing I heard was to think about my motivation for doing things...If it was in any way focused on doing for or controlling my daughter's actions, use, etc, then I needed to work on changing my behavior. If I did it purely out of love...as something I would do for a dear friend, and my motives were more "pure" I felt more comfortable with my conduct.
Sending lots of hugs...I'm sorry this is such a difficult time, but I am glad you are recommitting to your own recovery.