I'm sorry to reply your mail shortly. I know you are waiting for a letter from me. My job was very busy. But I do not forget to think about you. I think about you all the time.
I'm sorry that your mail is slow. I know you are waiting for a letter from me. This very busy during my work, but I do not forget to think about you at all. I think about you all the time.
I'm sorry that you have a slow response letter I know that you are waiting letter from me at my very busy, but I do not forget to think of you, I've been thinking about you.