I'm so very sorry for this sudden and unexpected loss. What a handsome boy! Just beautiful.
I know words don't help much right now while everything feels so raw, but just the fact that he passed away in a home where he was loved instead of passing in a shelter will hopefully bring you some comfort. You provided him with a loving home and everyone tried their best to find out what was wrong. His passing on 9/11 is quite telling as well. He's left you, but you will always remember your boy. I had rescued a dog from the shelter who was on death row and he was only with me for 10 months before he had some type of brain aneurysm and needed to be put down immediately at home. I took comfort in the fact that he passed away knowing he was out of the shelter for good and that during his last months he was loved until the very end. I'm pretty sure that your Champ passed away grateful to you for that short time he had been with you. Sending you peace
Mom to Millie, Roman, Snoopy & step sister to O'Boy