Hahaha.. oh the irony if that is the cure..The cure was to shell a green pea and feed the fish the pea.
Don't be alarmed by their quirky behavior. It is quite normal for them to hang upside down in a cave or under an overhang. They can also hover at an angle with their head down. Darting in and out of the rockwork, they can be secretive, hiding among the rocks and coral. Holding their own with most small fish, they will threaten them by opening their large mouths
http://www.marineaquariumadvice.com/Gramma-Loreto-and-Chromis-Viridis.htm