Poppy ended up going back to her normal self, eating, drinking, vocalizing and moving around her cage yesterday so I am pretty sure she is okay. Thank you for the resource!
Could be a concussion. I don't know if you're on Facebook, but there's a group on there called Parrot First Aid. They're excellent at giving first aid advice. Might be worth joining and asking them. I know with a concussion you don't treat with heat because that can cause additional swelling, but that's about all I can remember.