Good god man that's awful right before Christmas.
You have my sympathies.
Its no consolation to say this now, but at least he died peacefully in his sleep, even though 29 years old is far too young.
We just lost my 47 year old sister-in-law a few weeks ago. She was diagnosed with small-cell lung cancer 9 months ago. They call it small-cell cancer for a reason - its undetectable until it metastasizes and spreads to your vital organs. When you get the diagnosis, you're already dead.
She died a horrible disease filled death, even though her last couple of months she was pretty well comatose from medication. She didn't deserve to die. She was a single mom of 2 young children - 10 and 12 years old. Their father was an alcoholic who had nothing to do with them and never paid a dime of child support, yet he gets full custody of these 2 children and the only reason he even wants them is because the children will collect huge social security paychecks from their mom dying, until they are 18 years old.
She was a very productive woman - she earned her masters degree in Nursing a few years ago and was in charge of coordinating organ transplants at a major hospital in Phoenix.
I have sat around for weeks questioning why some people - good people die at a young age. People who were productive with their lives. Used their gifts to help others. People who have so many depending on them, and then poof.. they are gone, while other people - whose sole purpose in life is only to spread misery and harm to other people, get to live out full unproductive lives.
I don't have any answers, other than life is not fair.
But if your brother could say one thing to you right now, he would say to do your best to remember him fondly, but to let him go, and get about the business of making your life the very best it can possibly be.