Winning ranked games

Guys I need help. I'm currently dia 5 with 0 lp. I have 78 wins and 91 loses. I'm not ready to get demoted and I try my best but everygame someone is toxic and fucks up the game or all lanes lose and I'm the only one who did alright? Can you give me anytips? ( I main mid/ Katarina( shes banned everygame so. :D ) and lux . so whats the problem here?

P.S I do not flame and I'm positive every game.