Is it a HDD or an SSD/NVME?
It’s usually a very bad sign if all of a sudden you can’t see partitions anymore on the drive.
Basically, if you manage to boot and the drive gets properly recognized, you can either try to copy stuff off of it using standard methods. Or you can try some more advanced tools, e.g. ddrescue.
Sometimes you can get lucky, and it’s just a loose connection.
Oh, it’s most likely doing something. Just nothing you would want.