Can you please tell me how can i stay alive or make plays against sigma or domina??

i'm trying to stay away from meta characters like sigma,domina,ramattra etc..(plat lobbies).I really want to work with hazard,i ban domina so i barely see her but sigma is ruining my life so much,he is a pure poke machine and they also take ram or orisa to increase poke more,i know i'm not frontline tank but sometimes you gotta do that as well,i'm trying to go for backline but their sigma immediately helps and i barely escape or got killed,what do i do??? help me please!