I want to 2nd what dandy suggested - reading about it from the other side of the fence.
I read all KINDS of books & blogs & forums from the addict's POV. It really helped me to understand how, very often, even THEY don't know exactly why either. That it tortures them as well.
I'm not saying this allowed me to rush into acceptance but it did help me see how it was possible. It helped de-personalize my experiences & focus on the larger picture & future steps. It helped me to let go of asking these kinds of questions which stopped activating a lot of the negative thought patterns over & over again.
I mean, if someone caught in the spiral of themselves can't figure it out in any way & even after a period of recovery can't really explain "why" - I'd have to be God to have the all those answers myself, wouldn't I? For me - this was freedom from the weight of the albatross - I could see the choice I had in taking it off my neck & putting it down.