My 4 year old cat is extremely active and playful. When I got home from work today she was acting like herself - ready to play. A few hours later, her behavior completely changed. She became very lethargic and sickly looking. She is wobbly and was walking extremely slow -seems like her balance is off. Her eyes are also very droopy and she just looks miserable. She is now laying down and won't move for anything. She didn't eat her dinner and I haven't seen her drink any water either. She's been to the bathroom but it was earlier today. She is 100% indoors and has not gotten into anything. I don't know what would have caused her to completely change like this in a few short hours. Not sure what to do and I would appreciate any advice since I'm so worried about her.