Update PSU like you'd buy a new pc, grab a 6600xt then dish it out for a 9060 later, ditch hexacore and get a solid zen 3 used octacore maybe...RAM you'd have to decide, I'd say upgrade to 32.
PSU = <10k
6600xt = <13k --> 9060/9060xt (depends)
Keep the processor if it's not a daily bother or...