Sometimes I get so upset that I find myself reciting this prayer and saying "Amen." Is it a sin to do this?

Job Speaks
1 After this, Job opened his mouth and cursed the day of his birth.
2 He said:
3 “May the day of my birth perish, and the night that said, 'A boy is conceived!'
4 That day—may it turn to darkness; may God above not care about it; may no light shine on it.
5 May gloom and utter darkness claim it once more; may a cloud settle over it; may blackness overwhelm it.
6 That night—may thick darkness seize it; may it not be included among the days of the year nor be entered in any of the months.
7 May that night be barren; may no shout of joy be heard in it.