Had to put my 8 year old Cornish Rex cat down
several weeks ago she started losing control of her bowels and didn't have a solid stool. She would defecate while walking around and it would just squirt out of her like a sports bottle being squeezed vigorously. Then the walking became stumbling. Eventually plaintive meowing came into the picture.
I couldn't figure out what the problem was. We ran every test we could and tried all the different foods and medicines we could but there was just something desperately wrong with her. No cancer, no tumor, there was an absence of good bacteria in her intestines but the medicines didn't help her digestion or firming up her stools. Toward the end the stumbling turned into falling down and she ate virtually nothing.
It sucks, she was by far the nicest of the three I own, she slept on my chest every single night and purred me to sleep.
I imagine the vet was surprised (maybe not, he's probably seen it all) that a big skinhead looking guy in a leather jacket was bawling and coming unglued over a little cat, but I just couldn't shake the sense of loss and the guilt of not being able to figure out what was wrong with her. Bawled the whole time I was digging the hole in my backyard too and while I picked out and put a little statue on the grave for her. I do take a little comfort that she died with me holding her in her favorite way, with me whispering in her ear that she was the best cat I knew.
Note: this picture is not my cat. I'm weird about posting personal identifiers online, EXIF tags and such. But this cat is a dead ringer, identical in almost every way. Anyway, I've read enough threads to know DU is a good place to throw stuff like this into the wind. It's cathartic. Thanks for reading.
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Very hard to lose them, but I hope you take solace in your wonderful memories of her.
All the kind words are definitely appreciated. 
of course you are going to come unglued. I am very sorry for your loss.
Losing kitties makes me cry, even f I don't know them. They are wonderful little beings and I don't blame anyone for bawling like a baby when they go.
I'm guessing your girl had a noble soul...
Hope you can find some peace soon.
Rexes are lovely cats. I'm sure yours was a sweet baby. I'm sorry you lost her.
It's always hard when they go. 
Your cat was so fortunate to be so loved and cared for. The love you shared together will always be with you. Wishing you comfort during this hard time.
I have always had a *lot* of feline companions, and so I have also experienced many passings...
...I know how hard it is.
Kitters are special folk.
Peace and healing to you. 