I got stuck in a reboot loop trying to install Mac OS Big Sur and apple support told me i'd have to erase my mac. When I started it up again, Macintosh HD had disappeared from disk utility, so when I try to reinstall Mac OS there is no disk to install it to. All it shows me is APPLE SSD AP0128M Media in internal, and macOS Base System in Disk Images. How do I get Macintosh HD back?