Welcome dear. I understand being shy about talking to your parents about your problems. But they love you and surely would help you. How did it go that time that you emailed your mum? Were you more comfortable? Also if it's about a different topic now, you could try writing a message to her telling that you feel depressed and very shy, and you would like to find some help. A psychologist could help you. I'm sure that your parents would help you finding one. Or maybe there is one at your school.
Good luck, and if you want to talk feel free to message me