BIG hug for you Connie!  When you have more than one cat these things happen.  Don't forget that as you are stressed out, so is Bubba, and he doesn't even know what's happening.  I know it's difficult at the moment, but you have to stay strong for Tigger and Bubba.

When we were dealing with our dying cat Purrdita (the one who turned up starving on our doorstep on Christmas Eve last year), we had built her kitty steps to get down to her litter tray from her chair but she decided to take a flying leap and badly sprained her wrist.  We felt dreadful about it, particularly as it dropped her quality of life to such an extent that we had to have her put down as she couldn't push herself up to eat, even with the bandage, and just gave up.  It probably, acording to the vet, didn't shorten her life by more than a few days but we still felt dreadfully guilty about it.  We shouldn't have done though, as we couldn't do anything about it.  Cats do their own thing, it's what we love them for.

There are good times and bad times when you have pets and this is one of the bad times.  As not quite dispassionate (all right, quite passionate) outsiders, the news from the surgeon could have been a whole lot worse.  Tigger still has a chance at surgery which could give her some more years of life. We're rooting for you all and thinking of you all.