Great news!
I was able to solve the issue. By temporarily booting up Zorin through the NVME (still not sure why that appeared), I decided to follow one of the solutions from @Aravisian from this solution. Did some tinkering first because nvidia-driver-535 and nvidia-driver-545 fixed the resolution, but permanently set the color to warm for some reason. Downgraded it to nvidia-driver-525 and it solved the color issue, and I can boot it up again from the SSD without the previous issue.
In other words: the update that I did to my graphics driver caused a boot-up error, and purge-install it fixed the issue. Thankfully, if it weren't for the NVME boot to Linux, I wouldn't have been able to remedy the situation.