I don't think you need to buy a Score Preview, especially if you're going to take the test again (others might disagree but let me explain). In general, having multiple scores doesn't count against you when applying to law school. Multiple scores do matter if you do significantly better on a subsequent attempt. For an admissions officer, if they see you went from a 156 to a 168, they'd generally want to know what you did differently. The answer to that question is usually just, "I studied more/got a course." I might recommend a Score Preview for the second test only because you want that score to be better!

You are exactly right! Your brain is learning new ways of thinking and it won't be good at it immediately. As I worked through the curriculum, I found that some things made sense to me fast and other things took time to cook.