I can't seem to enter the overworld from the Nether

Dear Mojang.Today I was playing on my Android device the MCPE version.Everything worked normally until I went to the Nether. I began constructing tunnels to connect two of my Nether portals.While building,I accidentally hit one of the pigmen and ran to the nearest portal to try and escape as the Howard was chasing me.A I began teleporting I died and my game crashed.I gave it a few minutes and reentered the world and saw that all my items duplicated,As surprised and confused as I was,I stored the extra items away and continued with the tunnels.When I saw that I should probably go and restock my recourses,I made my way back to the Overworld.As I teleported the game crashed completely.I tried entering it I few time more but it kept crashing.So,as for now,I am stuck in the Nether.I thought that I should also mention that I am playing the beta version.I tried leaving the beta version but the game suggested that I uninstall the game. Unfortunately I couldn't do that because I can't backup my world.My storage unit was in application. I tried almost everything trying to backup my world but nothing seems to work.I don't want to uninstall the game for I have spent to many hours and have done to much work in that world that I just cannot part with it.English isn't my first language so please excuse some errors.Hope to hear from you soon.

-Minecraft PE Beta Player