I suggest you get an Corsair H80i or H100i, your cpu uses lot of power and runs hot.
These cpu coolers are also easy to install.
Make sure our ram is running at 1600 and set up correctly.
I suggest changing your power supply to at least a tx 650 however preferably a rm 650.
The CX series is not designed for hardcore gamers, I had one and upgraded to the 860i
Are you able to give back your 770? if yes get a reference 780 if you have the budget for it or a asus 770 if it fits in your case.