I would increase the temperature to around 28-30 degrees to speed up the life cycle, at 23 - 24 degrees it can take over a month for the cycle to complete, but you'll want to remove the shrimp first as they will not handle that temp. if you can remove the fish to a quarantine tank for a few of weeks to let the protozoa die off in the main tank, try a quinine based medication such as White spot cure.
Acriflavine doesn't do too much to the protozoa unfortunately.
remember whitespot is only able to be killed when it is not on the fish.