I'm so, so sorry. Maybe the vet will come up with something that will make her comfortable for a little while longer. I know exactly what you're going through because I was preparing myself for the same thing with Tubby the first time, but fortunately the vet said he was "salvageable." The second time I wasn't quite so lucky. Hopefully Sooty will be "salvageable" for a little while longer, but in the meantime, give her all the extra love and comfort you can, which will also help to comfort you.