If you're too 'fatigued' to work properly (ie bloody exhausted), do everyone a favour (including yourself!) and phone in sick.
No one's going to thank you for rocking up cream crackered and if you should screw up at work, it's no defence at all to say that you were 'fatigued'.
The company will just say that you shouldn't have been at work if you weren't fit to perform your duties. And they'd be right.
So it's either- 'man up' and shutup or....
Call in sick.
That's yer two choices. Bleating that you're shagged out will get you into a world of hurt. It's the same where I work.
Crying 'fatigue!', however well intentioned, goes down very badly.