I slept for 5 hours only last night and the next day I feel nausea, head ache and vomiting. It is always like this every time I sleep with 6hours less?

Sleep needs. vary from person to person. Some people feel ill or hungover if they don't get 6 or more hours while others can thrive on 4-5. You seem to have found your limit, so ensure that you get adequate rest. A healthy diet with adequate protein, fruits and vegetables will be helpful. Thanks for trusting HealthTap!