Why am I getting matched with these teammates?

I do want to mention I started playing League around February... However, in these months that I have played, it seemed normal to have a few regular games and then one horrible game and then some normals again, then a bad one again, etc... By the way, I don't consider all losing games bad games if we lost honorably...

This week and last, however, I feel as though I have been matched with a completely different "breed" of players.

Is it possible RIOT lowered my elo? I don't want to be "that guy", but these teammates... If it was just one or two games, I wouldn't notice; however, almost every single game these past couple weeks have consisted of horrible teammates.

So, you might be wondering what I mean by "horrible teammates". Well, these past two weeks, I have been harassed more than I have in the past few MONTHS I have been playing. I've been bombarded with sexism, blamed for everything, threatened, the list goes on... In fact, this last game, I got blamed because my opponent got fed; but, he got fed off my teammates, not me!! Another thing is that these teammates are the kind of players who seem to have NO sense of teamwork. Honestly, I would guess they have only been playing a couple weeks. They run around aimlessly, stupidly attempt to 1v3, have scores like this: 1/15/5...

Honestly, I'm getting depressed because of this. I go into games, not confident or eager, but thinking to myself, "another game to lose. I'll just try not to die too much, I guess."

I love this game, yet the PLAYERS are what are driving me away - more then ANYTHING else. Did I get put into a different pool or something? WHY am I getting these teammates???