If you did your best to write a complete, clear, and insightful essay within the time allotted, you should have nothing to worry about.
Once you hand your exam to the professor, relax! It`s easy to work yourself up after an essay exam when you didn`t get the chance to read your work over or you feel like your arguments were weak.
Some students react to the time pressure of essay exams by scribbling down their introduction as soon as they`ve read the question and figuring out their points as they go. While it might seem counter-intuitive, taking five or ten minutes before you start writing in order to draw up a plan will be an enormous time saver.
Do your research: Read primary and secondary sources and take notes to help you work out your position and angle on the topic. You`ll use these as evidence for your points.
Understand your assignment: What is the goal of this essay? What is the length and deadline of the assignment? Is there anything you need to clarify with your teacher or professor?
After the topic sentence, present evidence such as data, examples, or quotes from relevant sources. Be sure to interpret and explain the evidence, and show how it helps develop your overall argument.