Please consult a qualified Avian Vet with a history of working with parrots. If you live in a country or area where such a vet is not available, organise a Skype or whatsapp video call with someone who may be willing to help you out for free or a nominal fee.
Bumping thread for visibility. If only 4 weeks old, may not be fully weaned. Did you obtain from a breeder, or raising on your own? In any case, the advice of "Cardinal" to seek avian vet advice is best.