Copper or Hypo. Not both. Did you move the fish directly from the tank at 1.023SG to the QT at 1.015 (assuming your first post was a type with an erxtra 0 in it)?
How often are you checking Ammonia, Nitrite and pH?
If you did not take a filter from the DT to the QT you have no source of bacteria to start and the overload of fish could easily produce too much ammonia for the tank to handle.
Get a small power head in the tank to agitate the surface and get some oxygen in there.
Decide if you want to treat with copper or hypo and stick to one. You've already put copper in the tank so all equipment can now only be used in that tank, never transferred or used in the DT.
My preference is for hyposalinity as I think it is easier and safer than copper.
You might want to start thinking aobout 2x daily PWC
's until you get some bacteria going that can sustain the bioload. That could take a couple of weeks.