The truth is this, unless you are master tier or challenger tier level skill wise climbing the ladder is extremely difficult to do from roles that don't have a large amount of map influence. Junglers and Mid laners pretty much decide the games in low level play and its tough to find reliably good players at any position until diamond level and even then its not as common as one would like until about diamond 2-3.
The most important thing to keep in mind when trying to climb is that unless you are very skilled it will be a grind, so focus more on improving at the game. The most common thing lacking in players that prevents them from climbing is pretty simple, game knowledge and understanding. I'm a pretty awful player in mechanical terms, but I manage to do fine in diamond purely because I have a good grasp on the game, how its supposed to be played, what matters when, how to gain and utilize advantages, and how to organize my teammates. I literally get by just on warding, being around the right spots at the right times, pressuring the right objectives, and communicating what all these things are to my teammates and keeping us all on the same page. Watch streams, watch pro play, talk to other high level players, and work on game fundamentals and the climbing part will take care of itself in time.
Additionally, everyone is aware at this point that the ranking and matchmaking systems are broken and utterly ineffectual, you can't let that frustrate you, mental toughness is important. They are just as broken for everyone else as they are for you. If all else fails practice hard and strive to improve and then, when you feel ready, make a smurf account and try one tricking (playing exclusively one champ in one role) your best champ. 99% of players who do this achieve a much higher rank much quicker than they did on their main accounts. I make a new smurf and one trick a new champ to diamond every season (although I fell short this season with my one trick eve account and only managed plat 1, sad face).
Basically it boils down to working at improving at the game and ignoring the fact you will be forced to play with idiots, morons, and generally awful players the vast majority of the time.