I've been there! You should have shot a panorama!
Nice sky and overall mood in spite of technical issues. This would be good candidate for HDR or fusion, or at least separately exposed sky and ground areas. Sometimes just shooting about 8 frames at the same exposure and averaging them together with PS or Image Stacker can produce a surprisingly clean image in these circumstances, one that will withstand a lot of post work. At any rate it would help a lot to rubber stamp over some of those jpeg artifacts in the clouds using adjacent clean areas.