Dear [Name],
I am writing to apologize for my unkind actions. I know that my words and behavior have caused you pain and distress, and I am truly sorry.
I understand that my words and actions were hurtful and wrong. I should have been more mindful of your feelings and taken more care to be kind and considerate. I regret not being more aware of the impact of my words and actions on you and I apologize for the pain that I have caused.
I want to assure you that I am taking steps to ensure that this does not happen again. I am working on being more mindful of my words and actions, and how they affect those around me. I am also taking the time to reflect on my behavior and to understand why I acted the way I did.
I understand that it may take time for you to forgive me for my unkind actions, and I accept that. I am willing to do whatever it takes to make amends and to rebuild our relationship. I am open to talking about this further, if you would like to, and I am available to answer any questions you may have.
Once again, I apologize for my unkind actions. I am deeply sorry for the pain and distress that I have caused you.
Sincerely,
[Your Name]