Internal storage has been wiped out in blink of an eye
You've most likely deleted the storage folder seen in the PC view.

This folder isn't necessarily present in the root of your internal storage, it's more like a link to your whole internal storage. I don't know about how it's generated, but since Windows disrespect links, deleting it is effectively wiping the internal storage itself. I had this happened to me on my own Nexus 4, and restoring data was a painful process, and in most senses failed - most of my music files are only available as 8MB fragments, and pictures are distorted or simply unreadable.

Do check out the data-recovery tag wiki for tips on attempting to restore it, but as I said, don't get hopes up on restoring data in one piece.