So sorry for you that is a sad thing to happen.You must be very upset lose a sweet little kitten like that.
I think it was too much for her don't you? Also declawing is very traumatic for a cat and causes pain. If you get another cat try using soft claw covers instead.
Nail Caps for Cats. Also more info on declawing here.
article about declawing. I would choose another vet.
I hope that you are feeling better soon.
Tabby