I am so sorry to hear of your loss. I have found several of my hamsters in the same.. condition, and it's always horrendous. I really do know how it is, and right now, I wish I could give you a hug.
I know it probably won't make you feel any better, but I can tell you that it was a quick and painless death.
If there is anything I can do, and any more support I can give, let me know. I will be praying for both you and your bunny.