Before completely reinstalling I'd like to try to get some help here;
I've updated Ubuntu yesterday. After the next restart my system booted into the GRUB command line (as described in many other threads, e.g. https://unix.stackexchange.com/questions/474510/unwanted-grub-command-prompt-while-booting).
After following pretty much every guide I was able to execute the
boot command after
linux /boot/<path-to-image> initrd /<path-to-image> boot
But this doesn't solve my problem and instead brings up the BusyBox (like Boot drops to a (initramfs) prompts/busybox).
From there I'm not able to do anything;
fdisk does nothing,
reboot causes kernel panic.
I've also tried to boot from USB stick and ran
fdisk - but that didn't help at all.
Is there anything left I can do?
(I'm running Windows AND Ubuntu in the same system, on two different SSDs)