Are the scales sticking up could be Dropsy. A fish can live a while with Dropsy but should be treated with an antibiotic to get full recovery.
maracyn 1 and 2 each treat diff bacterias. gram positive & gram negative.
you may need to use both at same time to cover all bases.
I have seen it recommended before. both at full strength.
As always, I say experts plz correct me if that's wrong.
Best of luck with your oscar...