Given your current set up, yes the CPU is the problem there. It is unfortunately a rather poorly performing FX, when compared to the Intel offerings.
For your work load an i7 or Xeon would speed you up considerably, and perform much better in games too. In terms of buying a Xeon, if it is an E3 v3, then look up the i7 model with the same clock rate and you'll be looking at almost identical chips, at least for your usage.
Considering your RAM usage, since you seem to be bottlenecked by the CPU, it may go up slightly with a new chip. I would consider grabbing a combo deal if you can, something with an i7, mobo and 16gb of RAM or such. Combo deals revolving around the Xeons can be harder to find, however if you do not mind building it yourself, you're essentially getting an i7 without the onboard graphics, and at a lower price.
Also, if you do go for a Xeon, you will not be overclocking - so factor this into your motherboard requirements and save yourself a bit of cash. Perhaps put that towards 16gb of RAM or such.