Quick question, when you say you powercycled - are you using F12 to access the menu and clicking Shutdown, then starting it again? If not, there is a chance you've caused an issue with the card by powering off when a write was ongoing ( unlike real Amiga's where you can just flip the power off
)
I know it takes ages, but I'd use etcher and redo the card - I think that will be a lot less heartache than trying to repair the filesystem!