It looks like you are facing a difficult phase of your life. Is it just stress from school or are there challenges from other areas of your life as well? Some teenagers also have problems arising from their family and from their relationship. If it is so complicated and overwhelming, it will be useful to get professional help as soon as possible.
If the anxiety is just related to school alone, my suggestions will be:
1. Try practising a relaxation technique like progressive muscle relaxation techniques. You can try looking for a you tube video that teaches you how to relax by practising deep breathing and muscle relaxation techniques. Many of my patients report feeling more relaxed after they put aside some time each day for relaxation.
2. Sometimes it is helpful to write down all the tasks or homework that you have to do and learn to prioritise them. It will be good to learn to tackle one task at a time. For the more challenging tasks, you can also learn to break them down into smaller parts and learn to tackle a small part at a time.
3. Try going for walks for half an hour a day. This can be very relaxing and can calm your nerves now.
4. Some students find it helpful to study in groups.
5. Try talking to your best friend about your problems. If you all are classmates, he or she may be able to understand the challenges that you face.
6. You may want to seek help from a mental health professional so that your anxiety can be explored further. The doctor will also assess if you are depressed. Clinically, most patients with anxiety problems also have depressive features. There are medications that can be used to treat both anxiety and depression.
Do take good care of yourself and I hope you will feel calmer soon.
Dr Ng Beng Yeong