Okay, tonight's update: She ate a pinkie! I only gave her one, because she should be going to the vet on Monday and I don't want her to regurge any food. But this is the first time she's shown an interest in food since this whole thing started, so I'm taking it as a good sign.
No regurgitating either, and it seems like she may have slowed up on drinking so much, but I can't be certain. Also, those pink scales are returning to normal color with treating with betadine.

Of course she would start to improve the second I make a vet appointment. But still, I'm going to take her in to make sure everything is okay.