ChatGPT: Ran me in circles as you describe; suggested a number of things I didn't understand, including commands that don't work in the BusyBox shell. (It's not a normal shell)
Gemini: Nailed it on selecting an older kernel in the Grub menu.
This is why everyone in the linux world has a very sour taste for nvidia. It's not their fault per-say, but they did opt to go this route versus contributing their drivers to the kernel like everyone else.
I wish I could fix the things, I'll fully cosign the beef the hacker community has for Apple on that front. That being said, I don't see myself buying a Windows laptop anytime soon.