auch, that is a hard one. Mostly because editing and design work, and gaming need 2 different things. For gaming the CPU is not a high priority, but the graphic card is, on the other hand, editing and rendering, you need a good CPU but not that needed with a good graphic card. I am running 2 different rigs for my image editing, and my gaming. I dont know your computer you have now, but unless it is hopelessly aged, you should upgrade it for more modern gaming, and then build a rig for your work on the side.
What you need for a work pc. Lots of ram, and a big CPU, i am using Xeon E5-2687, 30 MB cache and 12 cores 24 threads and 3 GHz, but it would also break your budget with almost the double

But i would go xeon if you want a work pc. Just know that they are not meant for gaming. Dont think about the graphic card, unless you want to go 4k then you have to.
It is hard to say what you need to do to upgrade your pc because we dont know the spec. And it is also hard to say what you should put into a new computer, because we dont know how good or bad the old one is. Often you dont need a new CPU or ram, in most cases you can get away with just upgrading the graphic card. Gaming is not that demanding of your CPU or your Ram.