you should contact mojang via the mojang support/help page. Submit your problem here:https://help.minecraft.net/hc/en-us/requests/new
notes :
If you lost world too, try to make sure to check the world file in your storage. Then go to the settings in minecraft, then the profile section, change the saved data from internal to external. But if you don't find your world file, it means you've never changed minecraft settings so that the world is saved on an external.
I added a video snippet for this problem.
On my nephew's smartphone. it also doesn't even show the mojang logo/writing at all