Lifestyle
Breaks: Your brain is like a muscle, it needs time to recover from activity. If you work it constantly it will become overstressed, so do not exercise it non stop, take days off for sport and social activities. When you are taking a rest engage in activities that take your mind off work. It will be counter productive to use rest periods to brood about exams.
Sleep problems: Leave some space between revision and going to sleep. Do something completely different, so that thoughts about work do not spin around in your head preventing you from relaxing into sleep. If you suffer from insomnia bear in mind that the more you struggle to get to sleep, the harder it is to achieve. A good strategy is to prevent negative associations, by giving yourself about twenty minutes to fall asleep and failing that, getting out of bed for about 10 minutes, doing some undemanding activity and repeating this sequence for as long as it takes. Sometimes sleeping in a different place or position helps.
Try to avoid - late nights studying; alcohol (may initially make you sleepy but when metabolised can wake you up); and caffeine ( a known stimulant). Tired muscles produce soporific secretions, so some mild exercise at bed time might help. Pamper yourself - you deserve it! Eat good nutritious meals, enjoy long relaxing baths, have a mug of hot chocolate before going to bed - in short anything that makes you feel nurtured and cared for.