I've been losing a lot more lately

Now I know League isn't matching me up with Diamonds and Masters, but it honestly feels like I'm playing against smurfs almost every game all of the sudden.

Before I would win a game against completely under skilled players, then win an evenly match game, then lose 2 to 3 outplayed / counter picked games.

Now I'm just losing match after match for no apparent reason. Either my team acts up or their team acts together as a unit.

My match history used to look like; Victory, Victory, Victory, Loss, Loss, Victory, Loss, Victory, Loss (forfeit), Loss, Loss, Victory.

Now its; Loss, Loss, Loss, Loss, Loss, Victory, Loss, Loss, Loss, Loss, Loss, Loss Prevented.

Not even a joke... wtf is happening?