I was trying to free up some storage by deleting some apps, and suddenly all my images got corrupted and all I could see was a bunch of grey images with exclamation marks. So I came here, and one guy said: clear cache. So I cleared gallery cache and went into recovery mode to "wipe system cache" and rebooted my phone, and now the images are COMPLETELY GONE. Before I did what that guy said, the corrupted images were occupying tens of gigabytes of my storage, but now the storages is all freed up because even the traces of my images are gone. Why has this happened, what made that person give such advice, and what can I do to restore my images? Thank you.