How do you exactly Play her, what should I Do?

Heyyaa I'm a GM Sym Player but since Freja's release she's been a constant in my Character pool, even then I feel that I get killed tooo often especially against other hitscan.

I have good game sense and Aim, but I feel as if aaaalll of my knowledge over 5 years of OW goes straight to the ground whenever I play her specifically...

Soo any tips? :d