Ubuntu fails to boot failure reading sector

my Lenovo X1 6th Gen suddenly stopped working. I cannot boot anymore to Xubuntu. On startup I'm entering GRUB directly, I receive

ls
... (hd0,gpt1) error: failure reading sector 0x100800 from hd0

Websites suggest the HDD may be damaged, although it is pretty new (~2 months). I believe it could also be a problem due to an uncontrolled shutdown. I've tried many things like live USB, Lenovo diagnostics, etc. but they all freeze at some point. Any ideas how to restore the system or at least access the HDD?

If you can't access your HDD through LiveCD, LiveUSB, or diagnostics, it means that either it's faulty or its partition table is corrupted.

If you can see your drive through sudo fdisk -l after booting from Live media, you may want to try to do fsck on its filesystems.

Let's say you have 2 parititons on your drive.

sudo fsck /dev/sda1
sudo fsck /dev/sda2

Change the /dev/sda to the block name visible through sudo fdisk -l or list your parititons with sudo blkid.

If fsck can't fix your drive you may want to try use gdisk to verify its configuration. Please refer to this answer:

• Fixing corrupt backup GPT table?

If you can see the list of partitions on your drive you can proceed with this guide and try to recover grub:

• https://help.ubuntu.com/community/Boot-Repair

If you can't see the list of partitions please use SMART monitoring tools on live cd to check your drive for errors.

sudo apt install smartmontools
sudo smartctl --all /dev/sda

You'll find more on that in this answer:

• How can I check the SMART status of a SSD or HDD on current versions of Ubuntu 14.04 through 18.10?

If SMART can't access your disk it's most likely faulty and you should sent it to warranty. Keep in mind that you'll lose your data.

If you don't have backup and you don't want to lose something important, you're last chance will be this guide:

• https://help.ubuntu.com/community/DataRecovery