How do you apologize confidently?
Express sincere regret
Not only should you take responsibility for what happened, but you should let them know that you feel bad about how you made them feel. Some things you can say to express remorse and regret in a sincere way include: “I wish I'd considered how this would make you feel before I acted.”
How do you say sorry respectfully?
I (want to) sincerely apologize. A formal and polite way to say you're sorry. I'd like to apologize for how I reacted/behaved. Apologize in a formal manner or for something very serious.