Bug Lighting has inexplicably changed and I can't figure out what happened

So I've been working on a personal project of mine when, rather suddenly and inexplicably, my project's lighting just completely broke. For a long time I had it on pretty standard settings, directional light with mixed lighting and soft shadows, etc. About 30 minutes ago I was editing a prefab and must've pressed some shortcut or button (somewhere around the bottom-left corner, near CTRL, ALT, Z X C, etc.) because the game's lighting just...stopped working, and everything went dark and stopped reacting to shadows.

Here are two pictures, one of an earlier build when the lighting worked properly, and what it looks like now. Any idea as to what caused this or how to fix it? I've tried everything I can think of and can't find something that works.

I should also mention that the issue doesn't seem to be the materials, while they are my own materials, changing them to ones made with Unity doesn't change anything.

EDIT: I'm actually just a massive idiot, I added a cube onto one of my prefabs, and because of some scaling jank it ended up engulfing my entire game lol. If this post could kindly be taken down, I'd appreciate it.