Lost half my FPS today for some reason.

Ive seen the whole destiny performs badly on steam posts and i did notice that it was lower than usual for me ever since the update but a few hours ago it got so much worse. i used to get 100 to 120 fps consistently and it was like that in the morning too but suddenly im hitting 40 to 70 in every activity.

And this is only in destiny cos i tried overwatch and rivals and neither of them have any issues. Is anyone else experiencing this?