Just glancing at your stats, you throw games you should win. I see you consistently lose games where you have 15-20+ kills. That shouldn't happen. The only reason that happens, is you start dying. You start dying, because you think you are invincible, probably take really poor fights, probably dont play to the champ's strengths.
If you have 22 kills on Fiora, how do you even lose that game? I'm guessing you start grouping, start initiating because you think you are invincible, and start dying. You have to realize when you have 15-20 kills on your team, YOU ARE YOUR TEAM. So the minute you die, its over. I mean a 22 kill fiora, you could probably 1v1 anyone who comes to your lane, and depending on who they send, maybe 2-3 people. Why not just keep splitting, force them to send people to stop you, either kill them or allow your team some breathing room to catch up to your level of power?
I see this multiple times in your history. You have 15-20 kills and lose, and thats you throwing the game, not your team. There is nothing more you can ask for besides having that much power in a game. That is the equivalent of the coach giving you the ball, and telling you to go for it. If you are an ADC, obviously its up to you to win teamfights, if you are a split pushing dueler with 20 kills, its up to you to punish them for having no one who can stop you from taking objectives.
Also, you die too much. I imagine some of those 16/9 games, etc, you give up bounties and let the other team back in the game. Or, you probably die later on in the game, when dying is far more detrimental to winning. Its sad to say, that someone going 0/4 the first 20 minutes of the game, is not as bad as the 8/0 guy dying 4 times in a row 35-40 minutes into the game. The death timers make every death later on mean something, and the types of champs you play, make me think you die more at the end of the game, than in the beginning of the game.
Also, your CS is pretty poor. Looking at op.gg, you average like 1-3 cs per minute. Look at mine, I'm a silver player, I average 7-9 per minute. I mean all the kills and fighting make up for it, but you cant keep relying on that to win games for you. People dont understand the power you have by managing to get 160-190 cs before 20 minutes.
Anyways, thats all I can tell from your match history. Hope that helps.