Okay thank you I didn't know that! Whiskas was what my vet recommended, but as you say they may not know much about the exact nutrition. I will go out and look for one of those brands today.
The litter box is located in my room, since my housemates will not let me put it anywhere else. I don't think she's been startled by anything in here, since I'm often in here with her. But I will try cleaning it out completely today and see if that helps. Right now I'm using non-scented clumping litter. If cleaning it out totally doesn't help I'll look into trying one of the types you mentioned.
Thank you! Dino and I appreciate it =)