[Darcybaby]

Hello and Welcome to YT
I can imagine what is it for you to watch her like that and b/c we had a similar problem a month ago Just Want to tell you to be brave and try whatever you can to put her back in shape.
What the vets said ? Is she vomits right after she eats or bit later. Is she throwing up her food or is it a liquid (what color) ?
You can check on the bag of her food is there a citric acid ingredient, if yes the added water is not good (it has to do with some reaction in their tummies)
These Babies sometimes throw up if they eat more and/or when they are hungry.
Cerenia is a good drug (we use it too ) but if is not working for Sophie there is no point giving it to her.
How old is she and how much she weights?
I’m no expert and hope someone with more knowledge will answer to your post .