Macbook Pro Problem
So I was recently messing with my Macbook, and I deleted a file name Untitled, which I believe was the Macintosh HD file of this Macbook Pro 2015. I was learning how to factory reset my Mac by a Youtube tutorial. I accidentally erased something in that file. Then I shut off my computer and when I rebooted it there were a flashing folder with a question mark at the end. The when I open up the Macbook and try to re-download MacOs, but everytime it said that there was an error at the end. Then the Macintosh HD stop working and it can't be bootable drive. So I decided to created a bootable USB drive. I plug in a USB then download a version of MacOs using the MacOs utility. When it finish downloading, I boot it up but I found out that when I unplug the USB, the computer can't find any file and it can't be boot up. So one day, my USB broke and so I need a solution to successfully boot up my computer without carrying a USB around and so can you please help me?
MacBook Pro Retina