My cat won't eat, drink, or use the litter box. She has lost her energy and doesn't play or walk around much. Sometimes she also vomits, but not continually. We just moved and I thought she was adjusting to the change, but it's been 5 days and she hasn't gotten better. I have been force feeding her water from a dropper to keep her alive. I can't afford a lot of expensive vet tests. What could it possibly be? Anything I can do for her at home?