I am unsure what has happened...

I have an Ubuntu linode running 19.04. This is a personal projects node which was set up with ufw and fail2ban enabled for ssh. I also had MySQL set up with remote access allowed and occasionally used a remote desktop via TigerVNC.

I am wondering if my instance was somehow compromised.

I logged in this morning after a few days of inactivity and checked 'sudo last' and didn't see any successful logins from any unknown IPs which is just something I like to check occasionally. I was looking around and attempted to run 'ls' which threw an error something along the lines of 'bash: ls: No such file or directory'

At this point I restarted the Linode and now can't access it via SSH at all (ping times out). When I try to access via Lish I am stuck at the grub screen and can't boot because it says I need the kernel….I know this may be a dumb question but…was I hacked?