Is such depressing cynicism fun for you?

Tell me you’re an asshole without telling me you’re an asshole.

The powder coat is the enamel. It’s a ceramic powder that’s sprayed on and then cooked in a furnace.

You have etched it. That, I am sorry to say, is permanent. If you have access to a furnace you could try refiring it, a few minutes at 1500 f would do it, if it can be done at all. You’ve basically turned a smooth glass layer in to a kind of sponge. You need to melt that outer surface again.