So much packet loss since season 5

I was in my last promo game to silver 5 and was 2 wins 2 losses. I started the game and clicked on the minimap. Suddenly everything was standing still and I could move but I could not do anything with my abilities. Suddenly the screen said first blood and I was dead.... 20 mins later we lost but I got no loss forgiven even though this happened for the entire game. I don't know why this is happening, I have great wifi and a $1400 computer..... I SHOULD NOT BE GETTING PACKET LOSS.