Crosshatch trigger issue

[Daniel400G]

Hello Everyone,

I really need help with my crosshatch.
I purchased him 2.5 weeks ago .
Eating well and in a qt by himself.
I had him in copper for 2 weeks .
.4ish, not a .50.00
30 percent water change every 3 days
After 2 weeks I removed all the copper (cupermine)
The last few days of copper he slowed down, not swimming as much and yesterday I found him up side down not swimming???
He also has a brown stain on his face that comes and goes. It looks like a stain because there are no bumps .
I got a dose of nitrofurazone that I dosed tonight, is this the right thing to do? Is it an infection?
Please help.

 

[Daniel400G]

The trigger is 7 inch and in a 55 gallon qt tank right now.
If he is well he will be put in my main display 200 gallon system.