Elo doesn't measure how good of a player you are, it measures how well you play in a team of 4 other people.
Duo Queuing means you have a minimum of 2 competent people on your team that you can communnicate well with.
Play a role that you're strong at, but don't be that guy that locks eve with Promote/Revive if your lane it taken. Either suck it up or dodge yourself, don't punish other people for your inability to play more than 1 role.
Carrying a game isn't going 40/1/20, Carrying can mean doing 7/6/11, as long as you're the guy making good calls and setting up plays. As the jungler, take dragons when you can. As top or mid, grab a champ that can push/force out of lane, and consider grabbing teleport to go win lanes other than yours. Teleport Ryze, or a Roaming Morgana are good choices for mid.
Just remember that your lane is 1/5th of the game. Bot lane is 2/5th, jungle is 1/5th itself. Go help your jungler take their blue, or ward their red and take it if you see their jungler show up in a lane.