Wen u pray bout sumthin and have faith and it ends off bad why is that? How do u not get emotional?

I had a midterm(essay) today and I knew absolutely nothing about what i had to write. (this essay would make or brake me) however I did know one of the topics. But i didn't get to finish the essay due to the time that ran out. I pray about this so much and ask God to take control or atleast make a miracle happen. How do I not get emotional?