Just think of it this way... it is someones opinion on your level of skill. In a game of league of legends, one person can feed really bad until you cant stand a chance... Then you just die a lot and theres no way to get good stats for the match. then later on, your game is based on your stats... not skill. and now some bad newb just cost you this game and the next. then you get worse and worse people on your team... Hence Elo hell!!
If you are better than the people you're getting matched with, you have a statistically better chance at winning the game than the opponent because they have more people that can suck on their team (all 5) while your team only has 4 people that suck. If you absolutely can't win a good percentage of your matches after a long time playing, you're probably not better than where you are.
I took a quick look at your matches. You sometimes have very inefficient builds, you never buy Pink wards, don't drop many wards in general, don't swap for Sweeper when you get Sightstone (or don't get SS at all as support), and your CS is low. Work on that and you'll start winning more games. Just blaming your team and seeing no faults in yourself is a sure way to not improve.
Wut.
