Ok. This is usually not much of a problem, feed him plenty of live food and then he should recover quite quickly.
If you got 5 females then you should get fry soon, and they do store the sperm for several broods, so you should get fry [
Ways to stop fungus.....
What u want is malacite green, this is the best anti fungal chemical on the market.
mix to a 8% soluation and use over several days
Or a moor extrem way
Make a salt dip 1.5 table spoone to 1 point of warm water (as warm to the tank water as poss), add the fish to the dip, due to the different in salinty levels the fish should float.
Leave the fish to float/swim for about 1 min.
This is far from the best method, but if u suspect fungal infection it's a very good way to clear up the problem, quickly.