Everyone here is missing the elephant in the room: OP isn't "having questions" — she made a decision. Brother has reframed her position to be something he can mess with, and y'all, because of the conditioning we received, are going along with it. The crap she saw going on and distanced herself from — these things are not "questions". Rather the opposite: she's acknowledged and acted on what she knows.

OP, you were doing fine until you tried giving reasons. A bit of advice I once heard: If someone asks for your thoughts and then argues with what you say, they didn't really want to know. So let it go. Brother will see what drove you away when he's ready and not before.