sounds like you are at least getting your holes drilled, here in the missouri ozarks the ground is so rocky it is a real chore to build fence, i built a loading chute a few weeks ago, was setting wooden posts, the ground was soft, weve had a fair amount of rain here lately, but still with the rocks it was impossible to get my holes more than 20 inches deep, my best hole was 24 inches, had to use concrete to anchor them. my old john deere model B just dont have enough down pressure on my auger to help it much. one of my nieghbors stopped by while i was digging a rock out with a pry bar and suggested that i fill the holes with water for a few days to soften the ground up, i asked him how much water it would take to make the rocks get soft....he didnt know.....