Hi Senin,
These resources are developed for academic test taking, but they may help you as well for your recertification test:
Test Anxiety--UIUC Counseling Center Dealing with Test Anxiety Test Anxiety: Counseling Services, University at Buffalo CampusBlues.com - Test Anxiety http://www.sdc.uwo.ca/learning/mcanx.html University of Florida Counseling Center - Division of Student Affairs
Also try adding fish oil supplements to your diet and stop eating refined carbohydrates and sugars. Fish oil supplements can decrease anxiety.