Dear Brownmike,
You are amazingly strong and sane given all you have gone through.
I think Yoda might have a good suggestion. Maybe you can help your brother find housing elsewhere.
You've told your brother you love him. Continue to do it but it does sound like you shouldn't let him live with you. You cannot fix everything. If he is dragging you down, please try not to feel guilty for putting yourself first. If you go down, then you will not be there for your brother. You have a right to be happy/enforce boundaries. You sound like a good brother.
I can relate to not being able to rely on religion to help but it's good that you do not have any addictions.
Brownmike, you are dealing with more than I have ever dealt with. You are amazing and an inspiration. Sincerely, Myst