You have 0 nitrates? or you have not tested it? You may need 100% metro as the other meds are not pure.
To upload photos, send them to your self in an email so you can resize them. Take a full tank shot so we can see the substrate levels and a few of the discus. If you get your hands on pure metro, run the course 7-10 days 500mg per 10 gals. I dose 1.5grams in my 30g. Do this without skipping a day. Since they are not eating and they are in a 10g, I'd avoid feeding to keep the water as clean as possible.
What is surprising to me is that they died so quickly. Usually a discus with hex will last at least a month. I'm not sure I'd keep all 5 in a 10g either as it is hard to keep the water stable in a 10 gallon.
Did you get the other fish from the same discus source? did you QT the fish?