The "I Frew Up" Saga, day 2: Nvidia driver doesn't load when booting an older kernel, and is my plan re: initramfs reasonable?

TL;DR: I'm gonna wait to see if the next kernel update fixes initramfs for me so that I won't have to boot into an older kernel every time I turn on my computer. Also, despite Secure Boot being disabled, my Nvidia driver doesn't load when I boot an older kernel, so I'm thinking I should switch to Nouveau interim. The Nvidia driver was evidently the source of some graphical issues I'd been experiencing before The Incident.

Previous thread summary:

• I tried to do a system restore on my Linux Mint laptop yesterday due to some weirdness I was experiencing. This was apparently the absolute worst thing I could've possibly done in my situation, and to make matters worse, the system restore got stuck when rebooting my computer, so I did a hard shutdown. From that point onward I've gotten a kernel panic screen reading "VFS: Unable to mount root fs on unknown-block(0,0)" when I turn on my computer. This generally indicates that initramfs ("initial RAM file system") is missing or corrupted for the specific kernel one's trying to boot.
• I've been able to use my computer mostly normally by booting into an older kernel instead, so evidently initramfs is fine there. I've tried booting into three different kernels: the newest one I believe gave me the kernel panic screen; the second newest gave me a black screen I could turn into a terminal by pressing Ctrl+Alt+F1; the oldest one works normally. There are several more kernels I could try booting into, though.
• It was suggested that the problems I was experiencing that compelled me to do the system restore in the first place was due to faulty hardware, so I used smartctl and memtest86+, but both tests indicated as far as I could understand that nothing was wrong on those fronts: the former said that the "overall health test" was passed; the latter said "pass" after 20 minutes.
• I also tried using debsums but I didn't know what to make of the wall of text: a few things read "failed" but I could only see them for a split second, so I couldn't see which packages they were, and when I tried scrolling up in the terminal they were just nowhere to be seen.

By the time I logged off last night, I'd formulated the following interim plan:

My current plan is to keep booting into an older kernel until the next kernel update; hope that the update magically fixes everything; and if it doesn't, boot into an older kernel and try checking whether boot is full and then regenerating initramfs; and if that doesn't work, cry and do a fresh install.

So this is my first question, whether this is a reasonable approach to the situation.

Aside from that, I wanted to mention the following differences between how my computer's been running from the older kernel in the past day compared to how it's been running for the past few months:

1. The computer cannot connect to my TV via HDMI. It notices that I plugged an HDMI in, but just doesn't "see" the TV.
2. When my laptop's been asleep for an extended period of time, and is woken up, it does NOT have any graphical issues.

See, normally, to my chagrin, after an extended sleep, my laptop's screen will be black after I log in. Not on the log-in screen itself, mind you, only after I log in. My solution to this for the past few months has been to close the screen, then open it up, then log in again, and then the screen will actually show stuff after I log in. However, even then, the Firefox windows I might have open will not update their visuals until I grab them from the top and give them a little shake. It's like I can open and close tabs in fact, but the screen just doesn't show me that I'm doing stuff until I do the shaky-shaky, right?

But yeah, point is that I HAVEN'T had any of these graphical issues since I started booting into the older kernel.

And I happened to remember that the last time I had trouble connecting my laptop to my TV via HDMI, it was because my Nvidia driver wasn't loading. And so I ran nvidia-smi in the terminal just now, and lo and behold, it tells me that it can't communicate with my Nvidia driver. This to me indicates that when I boot into the older kernel that my Nvidia driver doesn't load with it. This explains both the TV HDMI problem and the lack of graphical issues: I don't experience graphical issues when the Nvidia driver isn't loaded, and I do experience them when it is.

This should mean that I'll be able to connect to the TV if I switch over to Nouveau as my graphics driver, unless there's some way to get the Nvidia driver to load on the older kernel. And I guess this was one thing I was wondering about: why ISN'T the Nvidia driver loading, when I've already disabled Secure Boot?

The good news is that my drawing pad and external microphone still work when booting the older kernel, and I've already finished my last time-sensitive projects in RVC WebUI, which is the only thing I really need the Nvidia driver for anyways.

So… I guess I should select Nouveau from the driver manager and restart my computer, then?

Edit: I couldn't switch to Nouveau in the driver manager because of some error involving dependencies.