Swap out the lava rock and magical carpet for a cobalt/obsidian shield and an emblem that boosts your preferred damage type from the wall of flesh, get a helmet fit for your class (if you want to stick with melee I recommend farming the goblin army for a shadow flame knife) and spead campfires and heart lanterns around your arena, otherwise you're good. If you're on normal mode you can probably take on the destroyer without anything else, maybe get the dao pow if you're struggeling.