Bad team. They dual adc'd and First Blooded to you at jungle gank. You also had double Heal. As a result you got easy turret plates, and Sivir pretty much carried you until 6, and then you stole kills off her with R/killed runners.
Other team didn't build any armor penetration at all, and Xayah also afk'd early/began inting (no CS to speak of, no items, no fight contributions)
Tbh, you suck hard. You placed 5 wards the ENTIRE GAME. AS SUPPORT.
If this wasn't Pre-Int-Season, you would have gotten trashed.
Possibly just terrible matchmaking.