That's a long, long time to go without updates.
I don't know if this is going to fix anything, or break something else.
Linux needs updates, just like any OS. It just doesn't force them on you. I'm unfamiliar with modern Windows, but my observations back when were that Linux got *more* updates than Windows - largely 'cause the whole OS happily updates everything from the package manager. The kernel itself doesn't get all that many updates.
So, yeah, I hope you've now run those commands. I also hope your system boots when you're done.
Good detective work on Condobloke's part! But, no, I was just checking in quickly to view the responses so that I would know what's in store for me later. In reality, it's neither of the above. I haven't done anything yet! I'm kind of in paralysis mode based on your "I also hope your system boots up when you're done" admission.
Lesson learned (the need to be a lot more diligent about updates) going forward, but right now I'm just worried that the cure could end up being worse than the disease. It sounds like I might need to wait until I can afford to be without access for a little while in case things go wrong, and honestly right now is not really that time -- at least not today.
So unless there's some kind of safeguard in place, it sounds like maybe I should hold off for now. If/when I do try this and things go wrong, I guess that can be a separate thread (written from, yes, another device!).