Incredibly frustrated

I'm testing tomorrow and my exam is in less than 10 hours. I've spent 3 entire months studying full time for this exam, destroying myself and gaining almost 20 lbs of weight, but before my exam, my own body decided it would be funny to play a prank on me and not let me sleep a wink. In the past 24 hours, I've only been able to sleep at most 2 hours (despite trying) and even now, my head hurts and my body still won't let me sleep. To top it off, my parents won't stop shouting at me. I know that by the time I write the exam tomorrow, I'll be struggling to even stay awake and I'll be fighting a major headache from the lack of sleep. It just makes me so incredibly sad and frustrated that all my hard work is going to go down the drain because my own body decided to sabotage itself. Like I can't even stop crying right now knowing that all the damn hard work I've put in is going to amount to nothing just because I can't sleep