Aw, sorry for your loss of your little peeper...
It sounds like you did try your best though, and that's all you can do. I have rescued quite a few baby (and adults) birds of all kinds. It is very hard to tend to there every need. I think I have rescued about 9 and (with the help of a friend) 4 have made it an been released in a park, but sadly 5 have died... You do what you can, and that's all you can do...
