Using dedicated graphics card creates endless loop searching for firmware in High Sierra

So I recently built a mackintosh, and have gotten everything working except for my dedicated graphics card.

• Intel i3-7100
• ASUS H110m-a/m.2
• EVGA GTX 570

I can use the integrated graphics on my CPU just fine with the right settings, however my GPU refuses to allow it to boot when it is in. I've researched that this card is old enough that it requires to have InjectnVidia (is that the case?), but no matter what settings are active (Inject nVidia, nv_disable=1, nada_drv=), it hangs on a loop for acquiring 'gfx firmware.' This is the last step to get my build operational, so any help is appreciated!