Who takes Nuvigil and what is your dosage?

My doc gave me samples last month.  After reading the warnings, etc I decided not to take it.  I just saw the doc again and she stressed how important taking Nuvigil was.  I told her I really didn't see a difference.  I was still tired and had no increase in energy.  The only thing I wasn't doing was napping during the day.  She saw that as a positive thing.  So, she insisted I get on a regimen of 150 mg a day.  I took one pill yesterday at 6am.  Although I was tired I wasn't able to fall asleep last night so I didn't take one this morning.  I don't know that I will be able to follow doctors orders on this!  I react very weirdly to meds.