Unfortunately the processor and the platform will hold you back. You could invest into a new platform while keeping your chassis intact but you'll miss out on USB 3.0 front panel connectivity alongside options to mount SSD's and other 2.5" drives which can be found on today's chassis's. 2018 will be pushing it by a long shot since game developers are trying to ask more from hardware's and are trying to push forward the boundaries for game details.
We will need you to list out your current system's specs as follows:
CPU:
Mobo:
Ram:
PSU:
SSD:
HDD:
GPU:
and that should help us pick out some parts for your upgrade though the most critical part is your budget which you have't stated. If there is no budget we could just build you a super...