My heart bleeds with you. I did not know what to do and called all over and went to different vets and finally had to put my kitty down in the fall of 2008. Haven't got over that yet. Later found a better vet and paid huge dollars for bladder surgery for our 10 year old cat. She is now fine and the vet said the first one could have been saved...if I had only known and gotten to the right vet.
I don't know what is best for your cat, but I do know how hard it can be to do the right thing and to find the right help.
Prayers on your behalf. Let us know how it goes.