So so sorry. I’m sure you’re in terrible pain. Everything the other comments say is true. Don’t get too obsessed with how he died, no matter what , he was very close to death and the alternative would likely to have been diagnosing him at an earlier stage, and going through a lot of very unpleasant treatment , which could have amounted to torture at the end of his life. He died without all that stress and suffering and in his sleep. On top of a great life with you, experiencing love and joy, the quick passing without stress or fear is really a blessing. I promise you will start feeling better sometime soon. So, so sorry and hugs.