I hope this letter finds you in good health and spirit.
First of all, I want to apologize for the argument we had the other day. It was wrong of me to raise my voice and get angry at you. I understand that I was wrong and I regret my actions.
I understand that our relationship is important to both of us and I should not have let my emotions get the best of me. I want to assure you that I will not let this happen again. I understand that arguments are part of any relationship, but I will try to be more conscious of my words and actions in the future.
I know that I hurt you with my words and I am truly sorry for that. I understand that I have a lot to learn and I am willing to do whatever it takes to make things right. I want to apologize for my behavior and I hope that you can forgive me.
I understand that it is not easy to forgive someone who has hurt you, but I hope that you can find it in your heart to forgive me. I want to make things right and I am willing to do whatever it takes to make it happen.
Once again, I am sorry for the argument and I hope that you can forgive me. I understand that it will take some time, but I am willing to do whatever it takes to make things right.