Oh Meghan, I am so sorry for your loss. It is hard but you did the kindest thing you could do for him, which is not make him suffer. I am heart broken for you.It was cancer. We had to have him euthanized. It was bad, considering how normal his behavior had been up to today.
Tito is... Not great. I think he knew what was up. He's being very quiet and while I hate to anthropomorphize him, he seems introspective and sad.
It's been a long day already.