Tiredness 9 weeks post surgery.. is this common?

The "Night Howls" thread began that way @shaz68.  I have now had a few reasonable nights recently but apart from those, I have not had a good sleep since diagnosis in Dec 17.  I can fall asleep given any opportunity but after a few hours, I'm wide awake.  So, I spend my days with constant fatigue.  You'll find many of us are in a similar situation - not unusual after such a traumatic time.