Image background layer missing in layers panel

I opened an image and added adjutment layers. The image is still showing in the workspace, but the image layer isn't showing in the layers panel. The adjustment layers are showing, but not the image layer. I looked in history and I see that I unknowingly created a group, but I don't see the group in the layers panel, so it's probably in that invisible group layer. I merged the layers just to see what would happen and it said there's no image, so I undid the merge. How do I get the image layer or even the group layer that I assume exists but I don't see, to show up again?