You will not be selected as a Questbridge Finalist if you discuss sexual abuse. This observation might evoke some ill will, but I’m a professional essay editor, and feel it needs to be said: decide if you care more about making a captive reader glance at a cathartic essay that will destroy your QB / admissions prospects, or using your admirable achievements to get into a top school that has the resources to propogate your worldview.
Absolutely do not mention sexual abuse. You’ve used it to strengthen your resolve and achieve some pretty great things - so write about those achievements instead!