Very sorry to hear about your loss. I went through almost the exact same thing with my brother about 10 years ago. He was finishing chemo for Lupus problems, and caught some sort of infection that could not be reversed.
He left behind two young daughters and a wife as well.
Every day is about being grateful for the time we have with our loved ones. Experiencing such acute loss brings about an awareness of self and family that many won't have until they experience the loss.
While fate was against your brother, he was a very lucky man to be able to spend a few more precious days with his family. And equally lucky to have family that cared so much back