There are a lot of different stories we can tell ourselves about what happened and why. I think thats one of our major tasks in therapy, to settle on a story. The one above still has you as the fallen hero? "If only!"

But im seeing your brother blocking you, probably because my brother blocked me. He recognized how tenuous the mother's love was. He tried to protect everyone from that, but that of course is impossible. There are not just two choices, to be in control and feel guilty, or to be out of control and feel fear. Just acceptance.