Hi jess, welcome to oscarfishlover. Sorry to hear this is happening to you.
Please wait for the experts for help. In the meantime this is what I would do:
Since your Oscar is very young, place him/her in a breeder's net (those that are easy to assembly, plastic frames, net as body) to simulate shallow water; place an airstone inside and keep your lights out. If you have a quarantine/hospital tank running, this would be a good time to use it,
It could be that something got stuck in his/her throat. Is there any fish missing? Sometimes they go after corydoras that has some nasty spines and end up in trouble. If this is the case you will need to wrap your fish in some clean cloth, use some long but smooth edged pliers (e.g. nose pliers) and gently remove what shouldn't be there.
Hopefully the experts will come around soon (they always do).
Pepe
Santo Domingo