I am so very sorry. I understand how devastating that was to watch. I had a bunny go that way as well. I know this next part may not provide relief, but it may offer a little comfort- “The fit” most likely was a post-death body reflex reaction and so your bunny wouldn’t be suffering during that. It sounds like something was wrong with him internally – Being an elderly bunny, could have been his heart, or maybe he had stroke or some other thing that caused his weakness, and so even if you had not brought him to the vet, this may have had happened at home, and I know you probably would have blamed yourself then for not bringing him to the vet. So there is no really good way around feeling of self-blame. You did do the right thing. Sometimes things like this happen and there is no blame – it’s just painful and our minds want to “solve” it — self-blame is way to figure out a way that it could have been “solved/fixed”.
You have been the most wonderful caring human a bunny could ever ask for. What a great life he had with you. He was obviously loved and he had to have known and felt that. It’s hard not to get stuck in the last moments. It’s painful. It’s normal to go through this. You will be in pain and mourn for awhile. During this time, be sure to try and get sleep, rest, be good to yourself. And when those “last” moments stab at you and you blame yourself, remember all the times he was happy and loved. Those are what matter.
Mourning is hard to go through. Hugs to you.
Binky Free Flopsy
(I say Binky Free here when a bunny has passed — just means they are no longer in pain and free from whatever ailed them).