To function at your best for work and school, you need to sleep. There are a variety of things that you can do to help yourself sleep better.  You do not need to suffer with insomnia.  'Sleep hygiene', including limiting screen time in the evening, keeping your bedroom cool and free from stress, and EEG biofeedback, can be helpful.  Also, consider how you take melatonin.  For more information, read further: Melatonin: The Sleep Supplement