negative win rate but still have higher mmr than my division. why?

So i'm currently silver. I've been stuck in silver for 3 seasons. I have a negative win rate in ranked but for some reason it consistently matches me against people who are in much higher divisions, often golds and even plats every so often. Whats the deal? why is my mmr in gold but i have a negative win rate. If i have a negative win rate, shouldnt my mmr be dropping and it should be matching me against other silvers? Im consistently getting full silver and bronze teams against half silver half gold teams like it expects me to carry them and i end up with a negative win rate. Despite getting matched with these people i ALWAYS carry the team and am ALWAYS the person who does the best on the team. I went through my entire ranked match history and there wasnt a single game where i didnt have the best KDA on the team. I asked some of my high ranking friends to take a look at my match history to simply look at the team ranks, and even they said it looked strange. so what gives? why is the system doing this to me? Can anyone explain this scenario.

if you dont believe me you can check my champion win rates and kda by season in the champions tab here: http://na.op.gg/summoner/userName=steliar