As of a few days ago I noticed my computer would at times lose its ability to connect to the Internet -- often still indicating it was connected, just not actually connected in practice -- and this was often accompanied by Firefox freezing, trouble shutting down, or failure to restart. The last time it happened, maybe an hour ago, I decided that the problem was severe enough to warrant me using Timeshift. And so I backed up all my files; tried looking up whether Timeshift was safe; and then bit the bullet and did the thing. But then Timeshift seemed to get stuck rebooting, so I looked up whether it was safe to do a hard shutdown, and it seemed to be, so I did it.
Tried to turn on my computer again and I was met with a screen reading "KERNEL PANIC! Please reboot your computer. VFS: Unable to mount root fs on unknown-block(0,0)"
Cursed a lot; messaged some friends about it but have only gotten read receipts and consolation; all I can think to do now is use my months-old live USB and just reinstall everything. Is there anything else I can do?
I'm just so pissed off about this, I swear.
Edit: I selected recovery mode from the bootloader and that fixed it. We are Back Baby!!
Edit 2: From what these comments are saying I guess things aren't quite so straightforward. I have no-one to blame but myself. Saiaku.
Edit 3: Looks like it wasn't the fact that I used recovery mode that let me start my computer like normally, but the fact that I chose the bottom option from the "advanced settings" list.


I see that you were able to boot the system. I still recommend that you do the hardware tests.
here's how to check the health of your harddrive/ssd:
this might not work if you have a nvme drive
should look like this
it tells you like how many times your harddrive has been turned on. zeros are generally good. if it says that there is some error greater than 0, that is maybe bad.
for example if "reallocated_sector_ct" is greater than 0, that is very bad. it means that you harddrive has had failing sectors.
there's a list of which attributes means that your harddrive is dying on wikipedia
https://en.wikipedia.org/wiki/Self-Monitoring,_Analysis_and_Reporting_Technology#In_ATA
here's how to test the RAM
then you have to reboot your computer and pick memtest86 on the boot options. it should take like 30 minutes or so to complete the test.
I have an NVME drive so the results I got looked a bit different. I saved them to a text document and sent it to my phone so I can try to figure out what to make of it. It says that it "passed" the overall health test, so I'm reckoning it's probably not the problem. I'm running the memory test now.
Rebooting the computer brought me back to the kernel panic screen until I rebooted it again, but this is what I expected to happen and I can at least rest assured that things work for now if I boot into recovery mode.
Edit: After around 20 minutes a banner reading "pass" showed up. It seems like it just loops until I stop it.
Edit 2: Also, turns out that the computer boots normally even if I don't use recovery mode, if I choose the lowest option in the advanced settings thingy in the bootloader. Choosing the top option I believe gave me the Kernel Panic screen, second from the top gave me a black screen that I could use that Ctrl+Alt+F1 shortcut on.