Lag and Ping Issues

Game slows down for 1 second and gets fast again and this happens always.

The game is too laggy and it is not smooth at all. I have seen a lot of problems like this but no real solution.

I have tried lots of setting through Nvidia Control Panel, in the game itself but no change. 

At first I set strand based hair to off and it became a little better but now it is the same. My settings are at ultra, i tried low medium settings but it didn't change. 

Lately the game shows this ping alert but when ı test my connection it showes 12-13 ping. I didn't understand this too.

Do you have any idea? It is too hard to play.