I'm sorry to hear that. When I had my transplant, I was told I had a 25% chance of dying in the immediate couple years after (as a young, otherwise healthy person), but, in the accommodation I shared with other transplant patients...it was closer to a 40%.
So I can tell you, the families and patients did appreciate those extra months together that they otherwise wouldn't get. Sometimes they had to keep staying at the hospital until they died but, a most I knew who died were able to go home, spend time with their family before their death. For some even those extra few months was more than they we've expected to get and they relished in that, they were able to make it to weddings, graduations and births they had already given up on.
You did good. A transplant is a highly risky procedure that is often, a last ditch effort for a cure. There's a lot that can complicate it, and a lot that can go wrong. But, even those who only got a little extra time counted their blessings that they did.