Grammar help

Hi,

Can you please help improve this paragraph style (intended for high school):

"I remember myself taking lessons and courses in High school and University days, reading all the material and theory, making homework, practicing hard, and finally ending up with an exam, catching me somewhat unprepared because it involved problems that include situations I didn't see before. I remember this to be confusing and it made me feel terrible,
As if no matter how hard I try, there will always be a catchy problem that will make me loose time and reduce my final achievement well below my expectations."

Thanks !