I understand how you feel 100%! It took me a whole year to pass the class, and my exam in prewriting classification had been returned to me to redo at least 8 times! Every time I thought I had a good essay it would never pass and then having to wait about a week for a grade...absolute torture!! But I passed that course with a B average and you too can and will pass!
Don't be so hard on yourself in you need a break from the class. Take you about 3 days to relax and regroup.
Follow the comments, from the instructors, to a T. Also don't be afraid to call the instructors to ask for help!
Google/Bing also helped me as I needed some examples of the types of essays I was to write.
Also, use the tutor service from Penn Foster, they help with essays also
email me: nhurey29@gmail.com
Hope to hear from you