curse the day (one) was born
1. Of oneself, to regret having ever existed, as due to some extreme suffering one is or will be experiencing. Basic training in the military is so hard that you'll often find yourself cursing the day you were born. She was so embarrassed by the event that she cursed the day she was born.
2. To detest someone to such a degree as to wish he or she had never existed. You're just a horrible, selfish pig, and I curse the day you were born!
curse (someone or something) under (one's) breath
To say threatening, consternated, or disgruntled remarks (toward someone or something) in a very soft or indistinct voice, such that no one else can hear or understand them clearly. "You'll get what's coming to you one of these days," Janet cursed under her breath. Steven stormed off to his room, cursing his parents under his breath. My dad spent nearly an hour trying to fix the engine on the side of the road, cursing the broken-down truck under his breath the whole time.
curse a blue streak
To use profane language with great rapidity and intensity. My dad cursed a blue streak after he found out I'd put a dent in his car.
curse (someone) under (one's) breath
To murmur something in such a soft, quiet voice that others cannot hear it distinctly. (Said especially of rude, unpleasant, complaining, or impertinent remarks.) I could hear Bill cursing the boss under his breath as he walked back to his desk after his annual review. If you curse under your breath around me again, I'll tan your hide so quick it will smart for a week!