our cat

We have a 15 year old cat. we have had her for 15 years. my husband is on his way to the emergancy clinic right now with her. before we moved we took her to the vet for a check up and let them know that her behaviour had changed majorly. until the last several months she was known as the cat who could not be touched by anyone but me. now she lays in the floor and they love on her. they assured us that she is healthy and doing great. so we move and she starts eating her cat litter and not going to the bathroom as much as she should. so this morning i take her in and they said she was a little dehydrated, that her calcium was high or low i can not remember. so they did a cancer test and it came back negative. so they pumped her full of fluid saying it would help her have energy. i picked her up at 4pm, the plan is to let her eat small amounts of this high energy food every few hours and bring her in on monday to see if she needs more fluids. so we get home and a hour later i give her a little food, she licks at it and goes back to sleep (definitly not the more alert cat we expected) a hour later DH takes her out of her cage and her head fell over. she is breathing heavy and just staring at him open eyed. we called the emergancy clinic and they said bring her in NOW. rob left about 40 minutes ago and it will take him about that long to get there. please understand this is hard on him all but i worry for rob because he had to give his dog away the week before we moved and this is hard. i gave him the option of staying home with the kids. he said it would be easier to take the cat. it is hitting michael of how much he has loss recently, his best friend, his favorite dog, his homeschool group and now his cat