sharky popped in and said unluckyblue can PM her about food.
Unluckyblue, I am sorry to dispute your dad, I'm sure as most everyone does, he has deferred to what he believes to be the expert opinion, he believes what the second vet has said which is ... it's a behavioral problem. A cat can and will go potty inappropriately when it is ill. Sometimes they just can't tell, or in the case of a urinary tract infection or something of that nature... it equates the litter box with where pain comes from. When the cat gets into the litter box, and tries to potty, it hurts. Therefore, in the kitty's mind, the litterbox is causing them pain. Your dad does not understand, as most people would not if they were not cat people, or had not experienced it, that this can be a cause of not using the litter box.
Please ask your vet to explain that some infections or problems *can* cause a cat to not use the litter box. It's obvious that the cat is not a priority in your parents' lives. I admit that I don't agree with it, but some people have different priorities than others and that's what makes this world go around. I feel, however, that YOU have different priorities than your family, or obviously you wouldn't be here trying to get help for your kitty.
Is your dad saying that you guys can take her to the vet tomorrow but basically it's to euthanise? Or is he saying that you can have one last chance to visit the vet and hope that the cat gets better, but if it doesn't then this is the last chance?
It's quite obvious that you're stuck in a situation that you're basically unable to do anything about between being at your parents house and they're at their wits end... not having the money to personally afford a vet.. I feel for you and your situation. I don't know what the outcome for Squeeky will be, even if you're given the time it takes to get her back on the right track (if it can be done). I guess what I'm trying to say here is that you're trying to do the right thing and you're fighting a lot of things that are blocking you. I hope, though, that if you're being forced to euthanise her without the express recommedation of your vet, that perhaps you may consider seeing if a rescue agency can take her or maybe if your boyfriend can take her if he's got his own place, or perhaps a dog crate for her until the problem is worked through? I understand your parents' impatience, as it would be something that would try your very last nerve if you were not a cat person (and sometimes even if you are), but I hope that you can find a way to give Squeeky every chance possible, and that may be seeing if someone else can help her or work with her at the very least until her issues calm down. Even if the vet finds out what it is, and has the appropriate cure handy, and you start it tomorrow... you're probably not going to see results within hours. You'll probably see some, but it's unlikely that Squeeky is going to be cured overnight.
I know you're trying really hard, and it's got to be really difficult for you. If there's anything I can do to help, please let me know. I totally understand and sympathize with what you're up against. If you want me to start doing research to find articles or something that would support it not being behavorial I can do that... then possibly you could print them out and give them to your parents? I just don't know what else to do to help you with this.
If there's anything that you think they might listen to, that I can help with, I'll happily do my best to help you with it.