i am so, so sorry for your loss - not just your brother's passing - but that he was taken from you so early in life - when you were the one who had most loved and nurtured and given to him. please believe this - that anything good that he was able to accomplish and achieve in his life - including the relationships with his wife and children - are a tribute in large part to the positive input and influence that you gave during his most impressionable years.
i hope that you will not be offended if i paraphrase Jesus - "Greater love has no one than this: to lay down one’s life for one’s (brother)." though you did not literally sacrifice your life in the sense of dying for him - you did sacrifice in a sense that you did lay down your life in so many ways - and gave up so much for his sake. and your sacrifice, painful though it was - did produce a wonderful life for him. i hope that is some comfort to you.
"That you are here - that life exists, and identity; that the powerful play goes on and you may contribute a verse. . . What will your verse be?" Robin Williams as John Keating in "Dead Poets Society"