Screen going all black after champion select

Just now, I went into champ select and everything went normal. After the champion select the loading screen starts, or does it.I tabbed out of the loading screen because I was watching YT videos and all of a sudden my screen turns completely black and the only thing I can see is the task bar. All the icons on the taskbar, I can hover over to see and they show me that program on the desktop, but I cant interact with them because the second I move my cursor away, the screen turns to blac again. Not even task manager could help. I tried restarting my PC but that didnt work either because when the my PC turned on again and when I opened League and logged in, the screen again just turned black and my cursor was showing that something was loading. Some seonds after I get 2 error messages that I couldnt interact with. I could close every app through the taskbar but the League TM client. I restarted my PC 3 times and it didnt work. Because I could see my desktop by hovering over apps, it lead me to belive it isnt to my computer.

Riot please fix your god damn game. Im probably gonna get a leaver buster even tho it wasnt my fault at all... I cant belive that after almost a decade this kind of stuff can still happend...[zombie-brand-facepalm]