It is not stupid. Feelings are never stupid. If you want to be there for him, I think the best thing to do is take care of yourself first. You deserve it. Know that forgiveness is easier than forgetting. Don't push yourself tho. Some people do change their present, but they can't erase the scars they inflicted on another.
Yeah, stats say most mol. were mol. That's not an excuse to go do it. & since he's done it again, that's telling you he cannot be trusted, Still. So no matter how much you love your brother, if you are back & forth w/ this, maybe cut correspondence w/ any of them for awhile. Get you back to you first.
People do change but it doesn't seem like HE wants to. My T always told me I should be w/ people who helped pick me up, not bring me down.
I hope this helps some. I understand tho. My bro hurt me as well. He died in '85 drinking/ driving. He was hurt himself... Still. You know what my dad said, If he wouldn't have died, he would've went on to mol. his own 2 kids. He mol. his sisters, wouldn't have stopped him.
This is tough. I so feel for you. PM if need to.
Love,
RM