Need advice

Stepping up from silver to diamond real quick needs a good couch or you must be talented. Getting diamond is nothing special due reaching diamond 5 need's only "game-understanding" all over diamond is pure skill. As the others said already you need alot of vision and a good over-view about the current game situation and how you want to influence the game into the right way you can carry. It takes alot of time, needs a lot of practice but in more than 3 - 4 week's you will play automaticly better and "even" when you lose your lane you learn how to support your mates in helping a fed team-mate to victory.