Whoa...
First, let's clear up some myths with the actual documented cures:
1. Hypo for ich
2. Copper for Amyloo
3. Formalin for Brook
Spending a few minutes on this site will save huge amounts of pain and suffering:
http://www.petsforum.com/personal/trevor-jones/fishdiseases.html
Given the measured nitrites, popeye, skin lesions, and clamped fins, the fish could be dealing with any number of causes outside of Brook, Amyloo, or ich.
At this point, waterchanges and hypo are a net positive regardless of the situation. Hypo does have some benefits beyond ich treatment, but it will not cure Amyloo or Brook. This is the hypo strategy:
http://www.petsforum.com/personal/trevor-jones/hyposalinity.html
Medicating with an antibacterial is not a bad idea, but I would use one that allows mixing with copper if required later.
I would not freshwater dip any fish based on the pictures, water conditions, and information at hand. There is far too little information to diagnose and medication in any direction is just a guess.
Waterchanges toward hypo.
Feed and remove uneaten food and waste 30mins later.
Possibly add something like Maracyn/Maracyn 2 to treat potential bacterial events.
Update us tomorrow and good luck.