OP i just looked into your OP.GG and ......you dont seem to realize a thing.
This is a team game.
No matter how much someone feeds, no matter how much someone gets fed.......there are still 3 other lanes with a bunch of people whose status will impact the game progression greatly.
Alone and fed as hell while your team got smashed as you farmed midlane for useless kills (killing same guy 4+ times). Game is hopelessly lost because 80% of your team is weaker than theirs......even if you do the work of 3 its not enough as long as they have two with the power of two each.
You died a bunch of time but all the other lanes won and even by a landslide at that? It means 80% of the enemy team is weaker and its a won game for your side, naturally.
To illustrate, i recently played game as Syndra midlane, i had rengar jungle, wukong top, jinx+thresh botlane.
Enemy side was Veigar, nunu, Tryndamere, twitch and morg.
In that game i got monstrously fed, enemy veig is a silver while i am a former plati, but my toplane and botlane both broke down and the Tryndamere even killed Rengar+wukong 1v2.
So, why did i win while 80% of my team was essentially down with Tryndamere pushing towers the second turret?
I smashed veigar and nunu into paste and force fed rengar and wukong with it, i smashed twitch to stop him from getting a true snowball rolling by roaming down on him and i gave jinx time to farm.
Then i turned toplane, i drove tryndamere into the dirt 3 times to have him stop pushing and drove the minions away and had Rengar+wukong roam together in the meanwhile which killed twitch&morg several times and got both of them back into the game along with thresh.
Veig had become entirely useless, morg was behind, nunu was behind and Twitch with his earlier lead was still pretty strong....if he was allowed to do anything.
Tryndamere found that he couldnt push top with me around so he started roaming......but by the time he did it was far too late, my team was already back in the game and no matter how he tried he couldnt even 1v2 anymore.
I won that game by spoonfeeding my own team kills, stopping enemies looking like they were about to snowball and smashed their strongest one.
That, is how you win games as a overfed midlaner with a losing team, not by ignoring them.