Do you take your BP at home? If so, is it normal? You need to find out if you have "white coat" syndrome or if you really have high blood pressure. In any case, you're going to have to find a way to get over your fear because medical exams come with the territory.
I suggest you get evaluated by your physician before taking your FAA medical exam. If you truly have high BP, relax. Generally speaking, the FAA will allow you to fly provided you can control it with medication and there's no side effects. You will have to jump through a few extra hoops, but it's usually no big deal.
Here's a good place to learn more, but your doctor should be your first stop.
http://aviationmedicine.com/articles...7&contentID=67