I'm 17 again

A light bulb went off in my head as I was reading the 2017 Literary Guide to Agents. I identified the feeling in my stomach as the same overwhelming anxiety I felt when I was  a 17 year old applying to colleges. First, choosing an agent is like choosing a college. I suspect the prestigious agencies look only at the proven. Not to say if I'm not a proven quantity, I won't apply. I applied to Stanford at 17 and was turned down. Turned out University of Pacific was a better placement for me. Hope I'll find a "Pacific" for an agent. 
The next step is writing a query letter and a synopsis to "sell" Invisible Injuries. This process is so similar to writing an essay to impress, I shudder. I knew how to write a personal essay, and yet I freeze trying to write a query letter and proper summation of the book.  I was on the other side of grading for too long.  I sympathize with  agents' feelings when they receive unsolicited manuscripts from hopeful authors. That sympathy leads me to  hope brevity is the answer. I tell myself, don't brag, don't drone on and on, be concise. Hopefully, the first two chapters of the manuscript will be good enough to attract someone to take a chance on the unproven.
One huge difference between 17 and 80 is when I'm too overwhelmed, I can stop, pour a nice glass of Chardonnay, sit on the deck and relax.