Can't sleep. Heart is really fast. How do I slow it. Have a busy day later. Don't have any time to be tired. Should I take red bull or not?
You should probably rest. If your heart rate is fast then the last thing you should do is dring a red bull/coffee. Try listening to some relaxing music and close your eyes. Think of something peaceful like what you are gonna do 10 years later in your life. You should fall asleep. Just put a timer on the music player or something like that. But trust me if you do not sleep you are gonna get very sleepy around the time you should be in top condition.
Try meditation there is an app called headspace that should help