Can only play one role at my skill level?
Recently I have learned that upon hitting plat, I cannot play anything at a platinum level except support. I've mained support since I began playing ranked in season 2's end. I landed in silver 1 at the end of season 3. Here in season 4, I hit platinum 5 about four or five months ago. When I get in ranked, I can ONLY support. (or i do poorly and cause the loss.) Problem 1: If someone else takes support... I'm screwed. Problem 2: I don't always even want to support. Like, Yasuo and etc. are fun champions, but I can't play them in ranked because I'm bad at their roles.
I feel like after watching multiple coaching videos online, I understand in-depth strategy, itemization, rotations and etc, but my mechanics with those champions and laning in those roles are not even par. I really like mid and adc as well, but I literally suck at them lol.
TLDR : Tips on how to be better at mid and adc mechanically, along with lane advanced lane mechanics?