Red gills is usually an
ammonia or
chlorine/
chloramine problem.
White fuzzy stuff is usually a fungal infection.
PimaFix and/or MelaFix would help with the infection, as would any number of anti-fungals.
Test the water and see if you've had an ammonia spike for any reason. If so, an immediate
water change followed by an extra dose of Prime (or equivalent product) will help deal with the ammonia.
If there's no ammonia, it might be that the fish has some sort of infection with a secondary fungal infection. If you have the tank, it would probably be a good idea to quarantine it in this case.