You would have to continue playing Ranked until matchmaking puts you at a place where you actually belong. (Win rate consistently stays around 50%) This is how the system works at the current state.
I recommend practicing on Normal games and focus on a few champions so that when you decide to play ranked, you'll be ready. (I prefer one trick pony: Pick one champion and stick with it.)
The game is all about grinding and gaining experience each and every game. Learn from your mistakes. Remember, League of Legends is a team based game and you play a huge factor in how a team wins or loses. So, don't worry too much about who carries and who doesn't because at the end of the day, you contributed to the win. All I can say is, play your best no matter what and you'll see yourself improving and gaining elo!
I'm impressed that you're willing to accept the fact that your skill level isn't at a satisfactory level. I have no doubt that you'll improve and climb the ranked ladder.