When you get into deep flow state, you become unstoppable.

I woke up at 4AM, worked straight for 7 hours straight.

No breakfast, just couple of glasses of water and a glass a milk.

In between I had this thought, "I should call them, and tell them, I can't do it, you guys find someone else to do the job."

I realized, I have started, so I have to go all the way in completing things. Else, all the effort would feel like it went in vain.