Dear Dina,
I was sorry to read your message, and I wanted to write straight away. I know exactly how you feel, because I felt the same way before my own final exams.
First of all, remember that feeling stressed is completely normal. It shows that you care, and you've worked hard all year, so you know more than you think.
When it comes to studying, I'd suggest making a timetable with one or two subjects each day, and sticking to it. Study in short sessions of about forty-five minutes, then take a break. Instead of just rereading your notes, try past papers and explaining topics aloud to a friend, which helped me a lot.
It's equally important to relax. Go for a walk or a run every day, get a full night's sleep, and don't live on coffee.
If you get stuck on a topic, ask your teacher or a classmate early rather than worrying alone. You can do this! Call me whenever you need to talk.
Love,
Diana