I keep losing ranked

Hello, I started playing rankeds not long ago (about a week till s6 end). Had a hard time playing and got b1 from placements. i started playing rankeds again this week, but I keep getting trollers in my team, team throwing games and being toxic. Even if my score is 19/8/11 mid, my team keeps suiciding and losing team fights. I keep playing with my friend but we lose every match and just get upset. Now I lose every game, it doesn't matter who i'm up against. i tried switching my lanes, I keep trying to help my team but it doesn't work. So any tips? Or should I stop playing League or rankeds? Because I'm not feeling any joy only dissapointment and ending up being sad. (Sorry for my bad english)