Missing or disappearing worlds when I uninstalled and reinstalled minecraft PE on Android.

Hello there I've recently been playing Minecraft on Android and I've been streaming called DMlightdum a world and my screen kept blacking out so I uninstalled the game reinstalled it, And when i clicked Application and External my worlds wouldn't show up I did click allow to my picture and everything and my worlds are missing I've been working on that lets play world for 2 weeks and that world it is very important to me the world is called Lets play - My World and yes I did put - in it