I started her on a dewormer about 24 hours ago and put some vitamins in her water, but she seems worse today. She,s just laying there now and I haven't seen her eat or drink all day. I know she ate some of the dewormer yesterday because I saw her eating.
You need to manually feed the dewormer to her, not put it in food or water and hope she eats it. This is especially important for a bird that's off her food & water. It sounds like you might need to start tube feeding this gal. Liquid first. Search for Kathy (casportpony) she has been awesome at helping people learn now to tube feed. Good luck with her!