If this has happened to you-- never fear.  You can overcome writer's block-- and here are a few suggestions for how to do that.

No, it's not.  Never give up!  Here is a tip that will make the early phase of writing that much easier: start by writing down ideas instead of trying to churn out full sentences and paragraphs from scratch.

Instead of jumping right into a free-write session, create a form of pre-writing that suits your personal style.  If you're a visual learner, for example, a mind map can help.  List some topics and put them in a diagram, of sorts.  Use large shapes to represent big ideas and smaller shapes to indicate details. Use arrows and connector lines to show how ideas are related. If you are a strictly organized planner, then a traditional outline might be your best bet.  The idea, here, is to begin thinking about the topic and to start defining your own point of view.  In writing, we often start from the general ideas and work our way to narrowing topics to reflect a more personal, insightful analysis.

Avoid sitting for a full hour or longer trying to think of a new idea.  

Take a break and come back to your assigned writing task with a fresh and clear state of mind.  Step away from your workspace and do something completely different from writing, and "get out of your head".  Later, when you return to writing, you might recall new facts, opinions, and viewpoints that you hadn't previously considered.

Maybe you're not sure what you think about a current event issue.  A great way to address this concern is to interview a friend or family member.  An informal question-and-answer session could be just the thing you need to put your thoughts in perspective. Hearing another person's perspective can guide you to your personal opinions and views with more fervor.

Regardless what you do, there will be times when the pressure to create inhibits you as a writer.  Writer's block is a normal problem, and it shows that you are taking your work seriously and care about the quality of your writing.  (That's a good thing!).  To overcome this challenge requires accepting that essays are never meant to be "perfect" and that each one of us has our own approach to writing. When you view writing as a process and not as a single-session endeavor, you will experience success and build confidence.