We've been there done that. Not a good situation all the way around, for sure. No need to beat yourself up, all you wanted was good for your pup and unfortunately our love alone can not sustain them.
our Polli was a very young 9.5. While coming up the steps , she tripped and fractured her left front leg. We amputated immediately because if the fracture. I'm not sure what we would have done had she not had the fracture. with the fracture it was amputated immediately or say good bye at that very moment. that wasn't an option.
so, we amputated-did chemo and had almost 5 months before we had to say goodbye,
best of luck with whaever decision you come to.