"Failed To Connect" I keep getting this message nonstop despite my internet connection working

EDIT 2: I can log into my account again, but the game I was disconnected from does not exist no more and there is no record of it ever happening. Really, really strange. I have zero clue what happened to that game last night, but I hope it never happens again.

EDIT 1: Ok there is something really wrong with the game I was in. The game started an hour ago and has not stopped according to my match history.

I was in a game as Ekko, was having a great start against Yasuo, going 3-0-1. All of a sudden, I start disconnecting. I figured I'll use a backup connection. That didn't work. I restarted my computer; that didn't work either. I restarted my router and modem. I made sure to test my connection by going to Google and other websites. My internet was working fine. I then tried to sign into League, multiple times; I get the same message "Failed To Connect".

What the hell am I suppose to do now? I'm trying to reconnect into the game over and over again, but I can't join. The game is still apparently going on as it has not shown up in my match history and according to my op.gg https://na.op.gg/summoner/userName=OrisaNeedsAHug if you check live game. I know the game time appears shorter, but the game at one point was at 40 minutes. I do not have a clue why my teammates would not surrender. I do not know what the hell is going on with that game, if its still going or not.

Anyway, what can I do in the future to fix this issue and prevent something like this from happening again?