In my situation, it took alot of pain for me to get to the point where I finally felt things had to change. Asking 'why can't I stop?' helping,, enabling, believing in....etc etc didn't bring me out of the problem.
I had to reach a point of intolerance to my pain & suffering in order to start doing things differently. At that point, discovering the 'whys' was not as important as learning how to save myself by living differently.
What worked for me was to learn about codependency, get some counseling, attend Al-Anon and come here to SR.