Sounds simple right?
Sit down and write.
In reality it's a fight,
head pounding,
drowning in wave after wave
of mind-numbing fatigue.

Disparate phrases don't easily segue.
Try, and try again. 
Fighting fatigue again,
fan on high, air in my face,
Music as loud as my head can take.

Some time later I awake.
Groggy, foggy, off for a coffee,
as frustration  builds.
I thought I knew my limits. 
Find a snack, 
get some fresh air.

Re-read the same piece of text.
The coffee's finally taken effect.
Just in time for bed.
Breathe oxygen  in deep, 
breathe out a prayer.

 Back to writing,
This time without fighting.