wtf just happened

Played a couple weeks of league and it was so nice... everybody playing well, games felt good and evenly matched...

Then all of a sudden as of two days ago just a constant matching with trolls and AFKs, at least 80% of my games have resulted in someone on my team either intentionally feeding over and over (REAL intentional feeding, not just tilted playing bad) or sitting at base for the remainder of the game blaming our whole team in all chat. I went from steadily climbing and feeling great about league to remembering why people call this the most toxic game, like a switch flipped. Is this normal?