[CLIENT] Sudden wave of incredibly high ping in-game(1500-7000), conection works normally otherwise

[Happened 29/10/2017 at aprox. 4PM UTC+2] As I was connecting to a ranked game, my client suddenly closed and said that I was unable to connect due to lack of internet connection. This was weird, as I had YouTube playing in the background just fine. I closed the web browser thinking it had caused the problem. As I tried to reconnect, the client would tell me the same things over and over again. Until the fourth attempt. In the loading screen I noticed that my Ping was at 999. I got concerned, so I opened a browser and checked my ping, dl/ul, etc. Everything was normal according to the internet speed checker. Now I connected to the game and things went wild instantly. My ping was at 1500 when I connected and would fluctuate between 1500 and 7000 ping, slowly increasing and decreasing. I tried to check what was causing this through the Riot's lag report screen, but for some reason it couldn't determine my current IP. It stated that I was in a location that I had never played games from before. After a while My team mates would obv flamed me, thinking I was trolling. I tried to explain to them what was going on, but of course my messages wouldn't go through. Or if they would, at an incredible slow pace due to the lag. And of course, every one of my messages was ignored. I got more mad as the flaming kept going on, getting worse as the time passed on. Teammates urged the opposing team to report me, told me to quit and they also said "Open mid". They also went to afk at the base at around 10mins. I didn't disconnect, because of Riot's bad habit of banning players in situations like these, without actually checking what was going on. At aproximately 18mins, the game would just stall and told me that it was trying to reconnect. I figured the game had ended, so I disconnected from the client. I was correct, it threw me into the match report screen. "Illegible for loot due to AFK behaviour" and a big fat D- for my efforts. I have no clue what caused this, it has never happened before. It couldn't have been a DDoS, because my internet was working normally otherwise. I'm too scared to play now, because it might happen again. My client is working fine, I can acces my profile, shop, etc. I have no actual tools to fix this by myself, so I made this post. Most likely getting ignored, because punishing people for saying naughty words is more important than fixing your spaghetti code infested game. Yeah, I am mad.