Pop OS 20.04: How do I switch graphics drivers (Nouveau to propietary) without messing up the display?

**Moved this question over from AskUbuntu.** I've looked everywhere online for a solution. I've tried multiple times to install the appropriate Nvidia drivers for my graphics card (**which is a GTX 680**). I've also tried blacklisting Nouveau, to no avail. I'm desperate for a solution, especially considering how a lot of games don't work properly with Nouveau. The only results that I got from attempting to install the appropriate Nvidia drivers were... bad, at best. Upon reboot, systemd would apparently works as intended. But, upon reaching a certain part in the init (around "Reaching target Bluetooth/Swap"), the upper part of the display is corrupted like crazy and the part below remains frozen. (see image below) Side note: this happens even when booting into multi-user mode. Also, **the card is flashed to work with macOS Mojave**, so I suspect that might be the reason why. All help will be greatly appreciated. Thanks in advance, as well.