Thanks for replying!
I checked the load option again, so here's what happens in more detail: When I click on load, it shows the load screen, but then nothing happens after that, even leaving it on for several minutes. The back option cannot be highlighted/selected, but it I move the analog stick you can hear the sound of the cursor moving. Pressing any buttons does nothing.
[Spoilers] Just to be sure, the ending is putting the stickers on the door and going through it right?