a mistake

Tomorrow, a mistake happened.
I didn't get up at that time when I need to work.
That's because I was so tired that I can't keep my eyes open.
So, finally I didn't go to work and didn't ask for leave before the work time.
It's my first time doing this mistake.
I was so sorry that I slept off that time.
It will be a lesson.
I should avoid to make that mistake again.
Sorry . . . . Forgive me, please.