Why am i losing every game to Tristana?

Hi guys, so this is particularly for vayne vs tris. Ok, i'll start out by saying that i know a large part of the community thinks vayne is completely broken and has no counter play, in s5 i hear you, really after you got your 3rd item the game became a joke, except draven, he can still 2 shot u any time. but since her changes in the preseason the champion is so weak its ridiculous, this isn't coming from some one with 50 games on her, i have around 700 games on vayne, im a 1 trick pony vayne main pretty much, yet since the pre season, i lose every fucking game against specific champs no matter how i seem to play it out, tris being one of them. I played yesterday a 5v5 with some friends, i laned vs a tris in bronze 4, witch is 2 entire tiers bellow my rank, she still beat me in lane and late game i was unable to come back. we did the same thing, now vs another friend playing tris for the 5th time....he wins....i know im not the best player in the world, not even by a long shot, but seriously, if you have that many games on a champion and you still can't beat newer tris players...there's a problem, actual skill seems to matter less and less by the day. how do you play this match up? am i losing something?