Problem With Rendered Images

Hi, I’m new to blender and I ran into this problem on a tutorial project.

I recently finished rendering some images for the animation, but when I went to put them together in the video editor in blender, they ALL changed. They basically looked like the 3d view of the animation, not the rendered one. Ex:

Just 5 minutes ago, the picture had materials and background. Even the desktop view of the folder with the pictures shows them rendered, but when I open them in blender, they show up like the pic. above.

I looked into the problem a bit, and I think it has to do with the fact that I accidentally clicked “Render Animation with OpenGL” in the Render menu of the video editor. I don’t know why it overwrote ALL of my image files. I have no idea how to undo this and I really don’t want to re-render everything for a day. Help would be really appreciated.