How am i supposed to do something as ADC??

i just played a ranked game.. the enemy had trundle, tahm and poppy, lucian and shaco. and i played tristana. my autos did 70 dmg to tahm kench while he had like 2k-2,5k hp already he bought only hp items and one sunfirecape and i had IE, boots and Rapid firecannon and they werent fed nor i was behind. our lee sin told me to buy AMOR PEN, so did i. and you know what? it did almost NOTHING its like i wasted my gold for nothing. i did like 10-30 dmg more per auto. i couldnt belive it. poppy can simply E me (wtf is this range?) and uses her W. what am i supposed to do? i cant use my escape because i'd get "punished" for that with a ministun. trundle is able to chase everyone down with DMP, boots of swiftness and his W + Pillar and tahm was unkillable. the whole game felt like they had better champs, not better skills. while they are tanky asf i and do more dmg than everyone else, i have to care about positioning, kiting, using my spells at the right time, get some peel from my mates etc etc. and for what? for doing almost 0 dmg to them.

nice marksman season, riot.