As the person who recognises and is aware of your actions and your mums, it is often helpful to think about her too. My mother is codependant, blind to the abuse, she neglected me. But to stop myself being consumed by my feelings I have to think about what was wrong with her because I like you were a child, and therefore you were not in the wrong.

I agree with open_eyes, I don't think you should use the word abused. from my own experience it creates more distance and it can be harder to look at. For me it made a negative relationship (with my mum) more negative and painful.

I understand you need closure too, you want to understand (I've been there too) but try not to ask yourself too many questions. Especially in a situation where you won't get the answers you want. That's incredibly painful road to go down.