Can someone explain this to me?

So, i just got demoted. And that is fine, i understand it and i'll play again to get promoted back. I just dont think it was fair the context in which i was demoted.

I've been struggling in gold 2, but i havent been losing every game. I'd say 50% win rate which is not a "you shouldnt be in this league" win rate(i think).

That's not it though. I've been in the division for some games, the max loss streak was 3 games in a row? i'm not sure. I know that i lost 2 in a row, but also won 2 in a row.

Well, lets get to the point. I lose a game, fall to 0LP, then i play this last game where i pick corki, end up 11/2/12 (S-), couldnt win because they had a better comp, in my opinion (And i couldnt push my feed, which was very hard in that game). So i lost that game, and i got instantly demoted.

How is that possible? That was one of my best games individually lately, its the only game i can say i lost because of my team, or because the enemy team. But not because i screwed up. I did really good in my first game with 0 lp and i got instantly demoted.

If you're just going to answer "Because MMR" please, dont, doesnt help!