Apologize to my husband and sister How to write short messages is more appropriate?

First of all, I want to explain why I wrote this letter to you. Sister, I think as your sister, you are really not qualified. I can't share anything for you, and I keep adding burden to your heart. Mom and dad wanted to hide everything in the house, but I always thought I was very tired, so I told you everything, which added an infinite burden to you. You are now facing the postgraduate entrance examination, and I keep bothering you, which makes you unbearable and so fragile inside. Sorry, sister.

In fact, sister, you really shouldn't be my sister, because I always ignore your feelings, always self-righteous, and always don't care about your tolerance. Sister, you are now a turtle carrying a lot of goods. With a shell for postgraduate entrance examination, I have to put a lot of worries on your back. I'm afraid that if I keep talking, maybe the next thing is the straw that crushed the camel. Now you are "Sister Lin", hiding in a place where no one is crying all day. You see, I am so bad, I won't comfort you, I can only add a lot of unnecessary burdens to you stupidly.

Sister, if you think this is an unnecessary apology, you are wrong. This is my sincere apology to you. For so many years, you have been silently undertaking everything and never blaming anyone. I don't deserve to be your sister. I always tell you a sad thing when you are happy, but it makes you feel ashamed and think that you don't care about others. No, no, sister, I should be ashamed now. I am willful, and I always feel that people around me are very fond of me and never care about others. Sister, I'm really sorry!

Sister, I have been your sister for eleven years, and now I know how much burden you have borne. I can only say sorry to you. I'm sorry!