Well the fish weren't in my possession for a little while and that's how they ended up this bad. Right now I'm trying to fix mistakes that were made

They are now at my place and I did a 100% water change a few days ago when "re homing" them, but the sores on one of their heads were really big and traveling towards the rest of his body and the other fish were picking on him because they knew he wasn't well. I started treatment last night and he seems to be a little bit better, he isn't hiding in the corner and he sometimes swims with the other fish again