"Bios has been reset" stuck on macOS graphic drivers after years of use without changes.

[suburbannun]

Hi there.

First of all, I'm writing this is a state of complete panic, I did install my system years ago, everything has worked absolutely fine until today.
Restarted my computer and got a message, "Bios has been reset" (?). Went to set up bios and it was half way configured, (?) but it has lost all the setups I had saved years ago and were working fine, some with overclocking and some without.
So I checked the Bios settings were ok, as fas as I can remember, and rebooted.

All fine until I got only one screen, I use three, and no Nvidia drivers were loaded. See the screenshots attached.
The Nvidia driver is there, no updates available after checking, cuda drivers up to date.
Select Nvidia Web Driver and restarted.

It all comes back the same, Default MacOs Graphics Driver.

I don't understand what has happened, I've been working on MacOS and Windows the whole day. Restarted and this nightmare occurred.

Now, I have completely forgotten everything about hackintosh and installations and what now, and this is my "production" machine and the only one I have at the moment.
I'm wondering, any of you with the time and patience to help me out to get this computer back the way it was?
Tried the forums, saw a really well-written guide, but I'm absolutely afraid to my bones to touch anything that right now I have no knowledge of and could make things even worse.
Oh, tried to restart from my backup SSD, same issue.

If you feel like helping, please let me know what information is relevant and I'll send it straight away.
Many thanks in advance.
g.

Edit 1.
Downloaded latest Clover v2.5k r5102 UEFI w/EmuNVR, but I don't get the option to customize the install as in the Solving Nvidia Problems Guide.
I'm wondering if it's "safe" to just install it. I mean, could I make things worse?

Edit 2.
Added
Code:
<key>SystemParameters</key>
<dict>
<key>InjectKexts</key>
<string>YES</string>
<key>InjectSystemID</key>
<true/>
<key>NvidiaWeb</key>
<true/>
</dict>
to my config.plist, nothing changes after reboot, selecting Nvidia Drivers and rebooting again.

 

[suburbannun]

Another odd thing, the boot drive in clover has been set to macOs for years, now after the bios reset thing, it's set to Windows (?)
I really wanna cry, please help.

 

[suburbannun]

Thank you all for your help
What a difference from when I set up this machine to now, I guess this road has definitely come to an end.

Anyway, just in case someone gets into this trap, updating Clover with "Clover UEFI Boot Mode with Emulated NVRAM v2.5k r5102", solved part of the problem. There are still issues I can't figure out.
If you're reading this, and feel like giving a hand, oh please.

Ya'll take care.
g