Login screen is black but icon, cursor and username are displayed

So I was in the middle of getting the latest software update when my macbook air went to sleep and i left it alone for a little while. I clicked a key to see its progress but it showed a black login screen with only my icon, my username and the cursor showing. Also the the top left corner, there’s a flashing cursor line, like when you’re ready to type but no letters show when i type. I don’t know what this is, I don’t know how to fix it. I tried turning it off and on but it’s still the same. I tried to do the safe mode thing but my volume is off and i cant hear the chime. Pls help?