I feel very nauseated. been up for 19 hours and i have to be awake for 5 more hours. what to do?

i have midterm exam in 2 days and its driving me crazy. i waited till the last minute to study. my head is aching and it feels i'm getting electric shock sensations inside the brain. i'm just feelin very terrible and stressed. in 5 hours i'm jumping to bed. what can i do to make these remaining 5 hours easy on me?