I am writing this letter to apologize for my words that hurt you. I am deeply sorry and regretful for my actions.
I understand that my words were inappropriate and offensive and I apologize for that. I should have chosen my words more carefully and not have said anything that could have been taken as an insult.
I want you to know that I did not mean to hurt you. I was in a bad mood and said something that I should not have. I understand that this does not excuse my behavior and I take full responsibility for my actions.
I understand that my words have caused you pain and I am sorry for that. I hope that you can forgive me and that we can move past this. I want to make it up to you in any way I can.
I am sorry for my words and I hope that you can accept my apology. I understand that it may take some time for you to forgive me and I am willing to wait.
Once again, I apologize for my words and I hope that you can find it in your heart to forgive me.