Macintosh HD missing and SSD duplicated

My MacBook showed the question mark folder instead of booting, so I tried to recover it using disk utilities and an external time machine backup. During the process the MacBook shut down, showing the question mark folder (and later crossed circle) again.

Restarting it in Internet recovery mode (Mac doesn't recognize a start up volume), disk utility either won't recognize any internal drives or it'll show "Apple SSD SM0512L Media" (500 GB full) and "AppleAPFSMedia" (500 GB not initialised) with subdrives(?) "Reboot", "Recovery" and "VM" (each 500 GB full and greyed out).

When trying to reinstall macOS Sierra the Mac isn't able to find a volume to install it on. Some of my research suggested erasing the AFPS container and the physical SSD but I am Wortes about completely "losing" the drives.