A few days ago, I accidentally replaced my desktop in Mint 18 with a virtual console with an errant keystroke.  Not having an obvious way to reverse the changes, I logged in and typed exit to exit the console and go back to the desktop.  Instead, the computer rebooted, and I lost God-only-knows-how-much unsaved work. After showing the Mint logo and flashing a message underneath it far too quickly to read, the computer now boots only to a black screen.  By pressing esc during reboot, I can get to a Startup Menu.  I ran disk checks and memory checks using it, and they all came up clean.  None of the other options in this menu help.  I have no idea what to do.The screen is clearly receiving power, and the black screen that it boots to shows a dash or underscore in the top right corner.How do I get my computer back?  It's an HP Pavilion laptop, if it helps.
Mint 18 will boot only to a black screen
linux mint;boot