I wish I wasn't as able to understand that kind of trauma as I am. I have also struggled to wrestle from my parents my responsibility for who, how, and what I am in my own mind, given too similar experiences with yours. While it's hard not to be bitter at abuse and neglect, I found it more affective that I lacked nominal guidance. However, I also am certain sure of things I have found out the hard way since, and that's a powerful benefit.
It also makes me prone to disagree, even if my natural inclination is to be agreeable. Until I am convinced I am wrong I stick to what I think is right, and all too often folks less aware of the differences than someone that learned them from at times catastrophic consequences can only consider disagreement to arise from disagreeability.
I feel fortunate you do understand the difference between disagreeability and disagreement.