I am really sorry, pale.emperor. I hope your brother finds his way out of the Watchtower in one piece.
I also attempted suicide when I was 16. My mother and I had just relocated to get away from my abusive father, with no help from the witnesses. I was so upset and disillusioned by how the elders protected my elder dad for so many years, and did NOTHING to help us, I didn't want to be a Witness anymore.
When I told my mother this, she said, "I feel the same way sometimes, but there's nothing else out there in the world". I believed her. And I decided I would rather die than live forever with only Jehovah's Witnesses.
It took me another 8 years or so before I was able to stop attending meetings and start to walk away completely.
My younger self couldn't see another option for myself outside of the Jehovah's Witnesses. I bet your brother is struggling with the same thing. His Aspergers only complicates it. I am so thankful he has you to help him get out. I had no one. I think I would have left sooner if I had had anyone on the outside willing to help me.
Good luck with your brother.