I agree with
@HeatherG, your little one should see a vet with these symptoms, and as soon as is practicable since birds are, unfortunately, very good at hiding illness until they can no longer do so. Bird physiology is very different to mammals so it's important to see an avian specialist too, rather than just a regular dog and cat vet. I'm not sure where in the world you are located, but the following list should help you to find an avian vet near you if you are not already familiar with one...
After a suggestion by a member, @Abu Colo, the Mod Team decided to create a list of veterinarians around the world who see birds. This was something we had discussed a few years ago, but the task seemed so large that we didn't get very far. However, the need is there and we decided that the time...
www.parrotforums.com
Wishing your sweet little Peep all the very best, please let us know how you get on