If anyone is wondering: I passed my exams, got into the best medical school in my country. I took 30 mg propranolol one hour before the exam. I don't know it helped or not. Maybe i could have done better without it because it made me feel dizzy but also i didn't feel any adrenaline rush so it might have helped. I don't care at this point. I gambled and i won.

For anyone reading this in the future: Be careful with propranolol. Figure out your opimum tolerability of the drug. Try different doses and make sure you don't get dizzy at that dosage. Good luck!