Orientation is probably the hardest part anyway and once you establish in your practice things may look a bit easier. working nights is not easy if your biological clock says you shouldn't.
I hope things get better for you and I'm sure they will. If not, you can always speak with your boss and tell her/him how you feel. I am sure that your manager would rather help you than be a jerk about it and risk you making a dangerous mistake because you are overtired.
good luck