Yes, this can be a very stressful test. Some people seem to channel the anxiety into a better performance -- and if we figure out how to bottle that, we'll be famous!
In terms of preparation for reducing anxiety, other than methods specific to anxiety (recreating test conditions, deep breathing, positive thinking), making as much of the test routine is important. It's harder to get stressed about routine acts. At the same time, unless you're really in the 180 range, there will be some questions that will be very tough for you, if not impossible, and so it's nice to remind yourself of this fact and let go of some questions. Here's an article about getting your top score that explores that a bit more:
http://www.atlaslsat.com/blog/index.php ... sat-score/Good luck with your new approach.