OK, sounds like maybe the filesystem got corrupted and that's preventing CicuitPython from coming up. Recovery involves erasing all of the file contents. But at this point I'm not sure you can even access them anymore. So you will lose any of your code (.py) files you had stored on the board.
To recover, try this:
First, download a 7.x version of the CircuitPython firmware from here:
https://circuitpython.org/board/qtpy_m0/
Put your board in bootloader mode and drag that UF2 to the BOOT folder.
It'll reset and most likely you will still not see the CIRCUITPY folder.
We now want to try to get the board into safe mode. To do that, press the reset button and watch the RGB NeoPixel on the Qt Py. Soon after pressing reset, you should see it flash yellow. When it does, press reset again.
Doing that, can you get the CIRCUITPY folder to show up?