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.
"Tell your heart that the fear of suffering is worse than the suffering itself... And that no heart has ever suffered when it goes in search of its dreams, because every second of the search is a second's encounter with God and with eternity." - Paulo Coelho