It's a fact that stress can keep you from achieving what you want, and that includes online education and exams. But there are ways to manage your stress and worry and make sure that what you learned comes out on test day.
Preparation is Key
The easiest way to not worry about an exam is to make sure you're ready for it. That means making sure you take good notes and understand the course material. The time to ask questions about material is not the night before an exam.
But within a few days of the exam, you should start reviewing your notes. Make sure that you highlight any areas that are confusing to you, and bring them up either with the instructor or with a fellow classmate.
If your instructor has given a study guide, try writing practice questions for each of the sections to be covered, and then answering them. If not, try to write out short notes based on the summaries you've hopefully been including in your notes.
Finally, the trite examples of sleeping well and eating right are actually true. It's based on making sure that your body doesn't go haywire, or that you end up feeling lethargic and unable to concentrate.
What About Last Minute?
If you didn't have enough time to keep up with your studies or just are a big ball of nerves, you still can do well on your exam. Deep breaths and meditation are two ways to get around the issues. But you can also combine the two.
One simple technique is to use the inhalation of a deep breath to express what you are stressed about. Then when you exhale, you say a positive result, like “I will ace this test,” or “I'll answer every question.”
Finally, don't make the tests that aren't that important reasons to stress out. Make sure that you weigh them appropriately so that you don't have a panic attack.