Mcbe world crashes when i try to load it up

It started since the nether update. i load up my game working on a tree farm in the end. i keep switching back n forth from the end to the overworld for resources. The game wasn't letting me pick up any items when i did this so i would restart my game. After doing this multiple times, i restarted it again because i had the same problem. but this time when i click on my world, it crashes. this has been going on for months and i'm so triggered by it. please fix this problem.