"Anyone else? I mean if I'd hit him in the face or something I wouldn't feel as bad as this....

I would feel sorry I had, but part of me is convinced this is worse."

And this is a VERY wrong conviction. People demonize sexuality in children. Maybe what you did wasn't something you should have done indeed but for heaven's sake - it's just something completely indifferent when it comes to your brother's future and his mental health. many years ago when kids weren't convinced all the time that it's something that horrible, they didn't treat molestation in terms of something worse than just spanking, health problems, a bad mark at school - al of those are unplesant but nobody in their right mind thinks such episodes destroyed their whole life.