How to carry games with E max

Hi i've recently picked up Sivir from playing her S6. I've maxed Q and W (first max) on multiple occasions but they've never felt substantial to living as an adc. I've recently started maxing E first on Sivir for sustain and survival (being E on 1 sec cd) and am wondering how to output more early damage. Currently, as it stands if I get to late game I have a lot of damage, but if most of my teammates lose lanes and I get roamed on the second half of laning phase then its either a surrender or the enemy pushing to win.

I am not asking to have my ways bashed, but to receive help on how to maximize damage early and mid team fights.