Yes, and I think I acknowledged that power imbalance between black and white people and ascribed it to social constructs.
https://dictionary.cambridge.org/dictionary/english/vulnerable
"Vulnerable (adjective): able to be easily physically or mentally hurt, influenced, or attacked."
Note: "easily physically [...] hurt". It's not about having mental decision-making capacity, but about whether someone can easily hurt you.
In a racist society, black people are vulnerable to being harmed because, as you describe from your experience, you lack social power. Institutions that should protect and serve you often don't. In a hypothetical non-racist society, that vulnerability would disappear.
By contrast, it wouldn't matter how non-sexist a society was, women would still be vulnerable to attack by men. We would still be vulnerable to forced impregnation by men. It might be rarer, and more reliably result in jail time for our attackers, but that vulnerability would still be there because we are smaller, weaker, and have ovaries and a uterus. And that's the key difference between sex and race.
You're right about there being parallels too: institutions that should protect and serve women are failing us, just as they fail black people (and in the case of black women, doubly fail as Jennifer Melle found out). If they were working, Nurse Melle, the Darlington nurses, and Sandie Peggie would not have needed to take legal action at all.
Nevertheless, the biological differences between men and women can't be reformed away and women will always be vulnerable to male assault and forced pregnancy through rape because of this.