The bloating is caused by an irreversable damage to organs (mainly kidneys) by bacteria or viruses. When it's a bacterial infection and it is cured by antibiotics, the organs won't recover. Sorry !!
I'm sorry, but it was for the best. I'm glad that method worked for you, but sorry that you had to use it at all. I've done it once. It wasn't a pleasant experience, but it wasn't additionally stressful because it did seem peaceful.
The other gourami seems lively and well, as do the other fish.. Considering a few more days of melafix to be safe.. Then change water and filter. The fish will be glad to go back to flakes! Although I've learned a boring diet week in week out may not be great for them so I'll change up a bit.. They can have a tidbit tab soon and I'll see what else I can do.