Dear Mary,
I heard that you often become sleepless because of worries about your performance at school.In my opinion,this is really unnecessary.
I also hope that I can always do very well at school,but I never let it become a burden on my mind.On the contrary,I always try to relax myself and make sure I get plenty of sleep every night.Only with full relaxation and good rest can I focus on the classes of the next day.
The other suggestion I want to give you is to have more confidence in yourself.Never doubt your own capability and always believe that as long as you focus on your study,you will be successful.
I hope my personal experience and suggestions could be helpful to you.If you have more questions,please feel free to ask me.
Yours sincerely,
Jim