Charlie,
I'm sorry to hear Riley's end finally came, but I'm glad to hear it was when he was surrounded by family, out in the real world. The loss of anyone to this sort of disease is always horrible, and with a child our grief is magnified. Finally, though, the horrors will fade, the healing take hold, and with a little luck, you and your family will be left with great memories of his strong spirit and the love he had for and in his short life.
I wish you all the best. I'm sorry for your loss.
J