Mary,
I'm so sorry for your loss. Buddy was a lucky kitty to have found someone to care for and love him. Rescuing is always hard knowing they have to be tested, and it never gets easy losing one soon after they come into your life. But you did the best you could, and he went to the RB peacefully, and did not have to suffer the harsh world alone anymore.

Amy, and my kitties Bailey, Cricket and Owen.