Better yourself
Instead of blaming the other players, find every opportunity to better yourself. Focus on what you need to do to become a better player in game and out.
CS a bit low? Work on last hitting. Time yourself. Trouble dodging skillshots? Work on your reaction time. Ganks need improving? Practice your timing and positioning. Trouble with counter junglers? Study jungle routes, know the routes of enemy jungler types so you can anticipate.
With every mistake, whatever your role, you can make it a learning experience and become stronger. Do your best, be positive, and try to show them how much an awesome player you can be. Now go out there and make the League of Legends a better place.