Screen turned black, won’t go away

I was loading up a ranked game, but the client music was still playing, so I opened up my client, and it half of it wasn’t loading in, as in the left half of the screen was just white. I think returned to the loading screen, but it went black, and there’s nothing I can do to stop it. I have tried ALT+F4, even turning the laptop off, nothing works.

Edit: it fixed itself after 18 mins, but by that point the game was lost