I really, really need help here. My cat keeps avoiding the litter box, and has been for awhile. She has now marked a huge part of the carpet and it smells. I've tried cleaning it, and she keeps using it. She has been checked out and has no health problems- I keep the litterbox, which she shares with one other cat, psychotically clean. I'm sure by now she just thinks that the carpet is her litterbox. I don't know what to do- I can't live like this anymore. I love this cat so much but I am at the end of the rope here- please. Any suggestions. I'm crying as I type this because I feel like I will inevitably have to give her to the shelter. Replacing the carpet is not an option.