Your champs for ADC all require peel. Your vayne and only averaging 148.9 CS a game is terrible. If you are going to play vayne, you need to practice it against Caits, Jinx, and Trist who pretty much counter her.
Take Riven out of every single role. I get it. She's fun. But right now you have a 31% win rate with her. That's forcing a champion that doesn't bring much, way too much. And you are barely going above KD. (6/5.9). If you were 10/5/9 or some crap on Riven with 31% win rate, then I would say that you can blame those games on your team. But you seriously are just forcing Riven where she shouldn't be.
Your vayne KDA is ok. But then you look at your Sivir and Lucian KDA and they blow Vayne out of the water. You just need to play the "brainless" champs. Sivir, Cait, Lucian, Graves, Urgot is ok, Kat is ok as well down there but not past mid/high gold unless lower end of pick order, your jungle champs don't go with the meta junglers of tank junglers. And all of them besides maybe kha if you counter jungle, suck against tank junglers. Top is ok with Swain, Lulu, and Vlad. If you can play Annie support, you can play her mid and you will be fine to carry. Every single player that I coach or talk to, wants to play all of these "skilled champs". Not sure why you do, but usual answer I get is "because they are fun and you can out play others." Which is cool and all of that if you don't want to climb. Just pick every easy champion.
Top: Mundo, Lulu, Cho, Kennen, Hec, Vlad, Shy, Sion, Mao, Shen Jungle: Naut, Amumu, Nunu, Mao, Sion, Voli, Shy Mid: Annie, Ori, Morg, Ahri, Kayle ADC: Cait, Graves, Sivir, Lucian, Jinx Support: Annie, Leona, Thresh, Lulu, Nami, Morg, can do Blitz in a pick out comp.
If you have the money, skill-capped.com is awesome at $7 a month. Their videos do help a lot. Go look at https://www.youtube.com/user/lastshadow9/videos and his videos. His verbal lessens are more on the mind set side of playing and he's where I got the "play easy as crap champs to climb" from, and his coaching videos are more 1 on 1 things.
I added you. I have coached many players and got them to Gold/Plat by talking to them/coaching. IGN is xFeelsbadx