What do i build in this situation?

This isn't a rage post (although i am unimpressed) its a genuine 'what should i have done?' post. I was vsing an almost all AD team, i had 325 armour, 4000 HP and a thornmail. and the Yi just melted me instantly every single time. so i want to know what i could have built/done instead to be the tank i was supposed to. if that build didn't offer any resistance against him, what else should i have done?
Report as:
Offensive Spam Harassment Incorrect Board