Maybe this will make you feel better, in human years he is 126 years old, hes had a good life, he will be with you forever.
My grandpa is still alive, still has a sharp mind, but hes almost 100 years old. Everyone in the family knows he could go anytime. He doesnt want us to feel sad when he passes, he wants us to have a party. He says "Ive had a good run"