mstrust: you're doing all the right things to move you through this - meetings, books, counseling, etc. Keep up that good work!
is it possible to block him from Facebook or from him being able to see that you are online or from him being able to send you messages instantly. I'm sure you get on there to relax and get your mind off things by playing games, etc., - and yet at the same time you are the most vulnerable to your brother's searching to-and-fro for a mark!