How do I carry ranked as a Platinum in Silver?

So I've been playing my ranked flex placements, and I ended up getting placed in silver. I don't exactly know why, or how my mmr is so low, because I am playing with season 6 golds and silvers (not many plats). In these games if I am trying my hardest, and am on a comfortable champion, then I will poke and play aggressive, while letting the lane push into me (minimizing the chances that I get ganked). **Something that I feel is important is that I will play aggressive (poke em down, but not go for kills) if I do not know where the jungler is, but if it is ev or shaco I tend to play a farm lane. If I am playing adc, then I won't go for kills until I know I can kill them, or if my support does something stupid and I feel obligated to help, of if our jungler ganks me. In Mid I will always look to get a kill, and try to poke them down while getting most of the cs, but I like to wait until the jungler ganks me to get a kill. I try to look at botlane to see if I can gank them both pre6 and at 6, so I shove the wave and start going down there, but most of the time I ping and say dont push and they are pushed to their tower by the time I get there. After laning phase, I try to transfer my lead to my team by moving around the map making picks, but not teamfighting just yet if we are behind. When I play, sometimes I end up doing the least damage even though I got fed, simply because my lane opponent also got feed off of other lanes and I cannot fight him without the risk of the jungle presence (evelyn). I really need to figure out what I need to do to start hard carrying these low elo games, but seeing how I am one of the lower-end plat players, (I honestly got there not because of mechanics, but of being able to cs, and being smart). I do not yet understand how I can decimate my lane opponent, and transfer my lead to my team. Thanks for the help!