It looks like you did not use the correct abrasive from the picture. You need to start with something that is a little more abrasive, but not too high of a grit because you need to be able to polish out the scratches, gradually. You start with a lower grit, then move to a very high grit (3000) over several stages. You can try wet sanding as well when you get to the higher grit stuff. If you dont sand down until you get rid of the rock marks (most of them, anyway) then you will never really be happy with the turnout, but keep in mind, if there are deep ones, you may not be able to get them out, only make them look a little less noticeable by knocking off the edges...