Turn off anything and everything that reduces jaggies. Reduce the long distance views some.
Close down all other programs when gaming.
How much memory does your computer have?
Which version of Windows are you running?
When it comes to video cards, x70 or xx70 is about where the mainstream gamer is at the time the graphics cards with those numbers are released. In your case, you bought a GTX 960. So that is one step down from the mainstream gamer, back at the time that card was released, a bit more than a year ago.
The we get to your CPU... Its an AMD CPU. That hurts you right off the bat. Even an 8 core AMD CPU will lag behind a 4 core Intel CPU. By a whole let. And you only have a 4 core AMD CPU. So I would rate your Athlon 860K as being roughly 1.5 Intel cores when it comes to gaming. And please don't think I am an Intel fanboy. I have purchased probably 20 CPU's in the past 25 years, and only my lest computer had an Intel CPU in it. The other 19 or so systems all had AMD CPU's in them. But the gap between AMD and Intel in games finally reached the point where I decided to get the best Gaming CPU that I could.
If you have less than 8GB of system memory, that will be part of your problem.
So from what little I know about your system so far, you have a very weak gaming CPU. You have a lower than average GPU. And a demanding game is dragging its butt in the mud... Sound about right?