Hey,
I think you may want a resting stop. The common symptom for noob quitting runners/jogger is not knowing it is perfectly OK to rest-stop or "walk it." I think the same applies for bike-commuting.
I regularly take rests at stop lights when I get tired. If there is no light, there is always some coke-machines, so I stop for an "Oolong". I used to go for Pepsi, but I am older now.
Tomo
P.S. You know I regularly stop to worship sexy bicycles. I think you can call that rest-stop too.