Inspirion 5680 GPU Upgrade

So I've browsed on here and other websites looking for suggestions and advice about upgrading my computer. I have the i-7 8700k CPU and a 1060 3gb GPU. I've been playing COD Warzone recently and I get dips to below 40 fps while on the lowest setting and lowering the resolution below 1920x1080. My computer is about 2-3 years old as well so I'm wondering if I should even bother with upgrading or just buy a different pc instead. 

I looked through many discussions and found videos of people doing this upgrade themselves however so much of the information varied. For example, one post said that a GTX 1080 was compatible with the PSU while another post explained how they had to upgrade their PSU to support a 1080. I have never built a computer and the extent of my experience is adding in an 8 GB stick of ram.

After some research I decided I wanted to pick the 1660 ti. I have no idea if this is a good decision and am worried I might need to buy other parts or run into issues with this upgrade. So my main question is if this is a good GPU to buy to upgrade this PC and if not should I buy another one or are there other options?