I downloaded the Chicago Resource Pack through the in-app store. Once it had loaded, my existing worlds had been erased. I searched how to recover these files (I do not see them in my phone's files) and followed a suggestion that said to toggle where Minecraft PE saves it's files. I went to the settings and changed where whether files were saved to the application or the device and Minecraft crashed. Now upon start-up, the app crashes after displaying the white title screen. I have restarted my device and forced the app to stop with no success in resolving the issue.

Any help in recovering my worlds and resolving this issue of crashing would be appreciated. Thank you!