I can't load worlds or servers or game crashes

When I tap my play button, it goes slow and I have to wait about a minute to see all of my worlds. However,it has done this since 2014, which I when I first got MCPE.
I downloaded 0.16.0 and when I tapped the play button it crashed. I kept tapping it and finally got onto the screen where I could see all my worlds and servers, but when I tap on one to join it, my game just crashes.