Normal game MMR

Is anyone else having a weird issue with it? I'm diamond 4 on my main, and play normals quite often and usually get matched with platinum level players..For the last month or so I've been playing in big 5 mans with a mixture of silver and gold level players, and usually we would be matched up against mostly gold with the odd platinum thrown into the mix.

Yesterday I decided to queue up by myself and noticed my Diamond 4 account was then matched up with 4 other bronze players on my team, and against a team full of bronze and 1 silver. I get in game and all these bronze kids are shitting themselves.. I drop 26 kills and carry the game. This happened two other games back to back last night.

Today I logged in and again matched up with bronze and silver level players. Now I know there is a ranked MMR and a Normal MMR, but the caliber of player I am matched up with and against just kind of stand still autoing creeps, not trying to last hit blindly pushing (you know that kind of player).

I have played about 9 games in a row with yesterday and today and have hard carried all of them thus far. Is there any way that me playing normal 5 man teams for a month straight totally fucked my normal MMR? How many more games of this do I have to play?