GPU Ram is far from being fully utilized with your current settings.
A proper CPU upgrade would certainly improve the situation and should eliminate the stuttering issues you have.
If you pick up a 5800X3D and corresponding motherboard, you get to keep your current memory kit, and could reduce your upgrade costs by putting your current CPU/MB on the used market. IMHO it would provide the best value and price/performance ratio.
A new Zen4 3D or high end Raptor Lake would do as well, much more expensive of course 