Looking to start streaming, needs some advice about hardware.

Despite having a built PC I am still kind of a noob with computers and so any help would be appreciated. My current set up is:

GPU: GeForce GTX760 CPU: Intel(R) Core(TM) i5-4690K CPU @ 3.5GHz Memory: 8.00 GB RAM OS: Windows 10

I use Shadow play to stream and for the most part it works, I just get a kind of low FPS. It varies between 14-30 which isn't the best.

My speedtest got me 66 mbps download, and 4.09 mbps upload.

So what should I upgrade if I want to see an increase in my FPS?