I have same experience in my first BB, I always felt excited so cannot fall asleep. After 5 days, I felt so tired and uncomfort, so go to my nantal doctor. She gave me some medicine that can help fall asleep, I took the medicine and can sleep. I only took the medicine for 2 nights, after that I can sleep as normal without medicine.
Therefore I suggest you go to see your nantal doctor, no sleep is harmful to your body.