Poor little baby. I am so sorry for your loss. I lost a baby last summer to FIP. At least I had some time to tell her good-bye.
This has to be very hard for you. I hope you can forgive yourself-remember, it is called an accident because it just happened by chance. It was not your fault. (((Kittylady))) from Becky and kits.
I'm very sorry, please remember he's in no pain and not suffering. He's watching you from up above and smiling down on you and wanting you to be happy now.