My world won't load

I was playing normally on my Minecraft PE world, and I type the /kill command into the chat so I can go back to spawn. It puts me on the menu with the options to respawn or quit game, I click to respawn and it doesn't work so instead I click quit game. I go onto the main menu then click on the world to play it. It starts loading and it gets to the final point and it doesn't load the world . I waited 5 minutes, nothing had happened. I restarted minecraft, and waited again, NOTHING HAPPENED. Please help me restore my world back. It's my best world. Thank you.