Black Screen of Death (BUG)

So my friend wanted me to spectate a game of his, so I hit Spectate Game. I then encountered a bug splat. I asked him if Sona was in the game and he said yes. BUT, there was no warning saying to not spectate a game with Sona in it, so I thought they had fixed it. Apparently I was wrong because when I tried to join again my screen went from the client to the pre champ loading screen when its all black, and just stayed there. So I turned off my computer and I logged back in and thought nothing of it. Then I joined a game and when Champ Select was done and it was time to load the game, I got stuck in this black screen of death. I literally am so confused. I just want to play league again. I uninstalled and reinstalled, and it did nothing, I still get stuck in the black screen when I want to actually get into the League of Legends program.