My landscape turned transparent?

Hey guys!
Pretty new to Unreal Engine, only started working with it for class and have had it for 9 weeks.
Was working on some landscape changes, mostly sculpting it out a little more to suit my level design. At some point, some option was hit or it glitched out, and now I can see through the entire landscape. While there is a direct light source on it, the landscape seems fine, except that any meshes that clip through, I can now see their black silhouette underneath the landscape. When there is no (or barely any) light, the whole landscape goes invisible, even though I can still walk on it. I was figuring it was either a lighting or texture based problem, but I’ve no clue what. Any help solving this would be as appreciated as I can appreciate anything, since this project is due Tuesday for me and I really don’t want to take this class again.