This is what happens if you get cute with the naming. Just call them chapters.
The endings are endings, because of the game's idea of cyclic nature of events. It's hinted that the events of the game aren't happening for the first time, but in fact, are a repeat of history.
That is, you are replaying the game as part of that cyclic nature. It's perfectly fine to stop the game at the first "ending" - but you will miss the total message of the game imho.