Looking for ADC Teacher

Alright so before all the haters start posting. Yes I am bronze 5. I know why and its because I suck. That is why I am here. I want to get better at ADC since it is my favorite lane to play. Lately I have been letting my teams down badly and I want to stop that. It isn't fair for them to be brought down by my inability to properly ADC. I currently have 4 ADC champions: Ashe, Varus, Tristana, and Sivir. I may have 1 more but I would have to double check to make sure. I mainly like to play Ashe and Varus mainly because I cant understand how to play Sivir or Trist.

My ADC build is Essence Reaver, Runnan's Hurricane, Infinity's Edge, Static Shiv, Blood Thirster and Blade of the Ruined King. I have found I work best with Thresh as my support though im not sure why, and im being completely serious there. My farm (usually) is okay. Being able to get about 100-150 CS by the 20 minute mark which I have been told is right where I need to be for it. IDK I am willing to bet its just the way I play. I know I am a very aggressive player. I like to fight. I know this contributes to a lot of my deaths but even if it doesn't I find that I am just over whelmed by level 1 champs just exchanging autos such as Miss Fortune and Lucian. Take a look at my profile and see if you think you can help. Thanks!