Skip the metro which should be used when absolutely necessary and by weight. In addition, this will not help with internal parasites in which by the looks of the fish, is not internal parasites but may be from excess mucus in the stomach lining especially if you are feeding mysis and brine shrimp. If so, stop the mysis for about a week and feed flakes and pellets and even LRS fish frenzy and you will see a change in feces color and consistency
As for breathing, this is labored breathing and add air stone and assure ammonia and nitrates not elevated. If using API tests, you may be getting false readings.
Do a water change and add an air stone to tank right away