Ok, so first, the good news. I didn’t get to talk to the vet or vet tech (I only talked to the receptionist this morning) but the vet came in, looked at her preliminary lab results and said it was an infection. Further, the antibiotic shot they wound up giving her right at the last minute when we went to pick her up is most likely all the treatment she’ll need. 
Now the details…
A friend of Love’s told him about the Credit Care Card (which I had heard of for like doctor or dentist visits for humans but I didn’t know they did for veterinary as well) so while Gracie was at the vet’s yesterday, I went online, applied and was able to get $500 in instant credit. Her bill came to $414 (including the last-minute antibiotic they wanted to try; it was $46 and they said it might help and certainly wouldn’t hurt. It wasn’t a huge amount extra so I figured we’d go for it. Glad I did.) and I was able to simply pay it with the card. They let you print up a form so you can use it right away instead of waiting for the physical card to arrive. They give you 6 months to pay it off interest-free too so that’s good. I’m hoping I can get it paid with the tax returns.
Gracie is doing a lot better too. Her mood is elevated; she’s perky and you can just tell she’s feeling better. She’s still peeing more than she should but nowhere near as much as she as Friday. The vet receptionist said it can take 48hours – 4 days to see the full impact of the antibiotic they gave her and the fact she’s doing better 24 hours in is a great sign. She’s been cuddling with us and purring and getting some real sleep too which she didn’t do at all Friday night.
Tomorrow, I’ll talk to the vet or the vet tech and get some more detailed info. Like, right now, I don’t know if she had any crystals or stones as well; I don’t know if there’s anything I need to do or watch for to prevent it from occurring again; etc. But, I at least have some relief from worry and some piece of mind that she’s doing better and the vet feels the results are pretty straight-forward.
I’m so relieved. I can’t tell you how happy I was to get this good news this morning. Our little Gracie is just such a part of our family and this has been a really emotionally trying few days worrying about her. So the good news is great news. Thanks for the thoughts and support. 
I used Care Credit for my laser eye surgery, worked out great. haven’t used it at the vets though.
Good to know. Someone was telling me horror stories on LJ and I got worried. I’ll just be diligent about it and keep an eye on the account.