Excellent piece of creative writing!  Great job.

Dear

Dear
　　Those The word, "Dear", takes me away to another time when we used to write to each other after mom and dad had died.

I used to tell you about new friends and my new life. And you used to tell me about the grand great times about my mom and dad were having in heaven. There is no such truth in these stories.is nothing.

What you believe to be true is everything. Truth is what you believe in1 And the main thing that I used to believe was that I would will be with you forever. Forever.

The reason it has taken me so long to write to you is that I see realized that I have had been such a fool. I've had spent my life fooling myself.

Every letter i've I ever had written to you has had been a love letter2. How could can they have been anything else!

I can see now that all of them, except this one, were bad love letters. Bad love letters begging for love back. Good love letters ask for nothing.

This, I'm pleased to announce is my first good love letter to you. Because there is nothing more for you to do. You've already had done everything.

I have enough of you in my head to last forever. So please don't ever worry about me. I'm peachy, I really am.

I have everything now. If I had have one wish, it would be that your life brings you a taste of the happiness that you have brought to had given me; that you can feel what it's like to love.

1.  I am guessing here using the words as clues.  Write in Chinese for accurate correction.  Some of us know Chinese enough to make the corrections.

2.  There is a big difference in the meanings of "love letter" and a "letter of love".  I cannot correct this unless I know the receipient of the letter is.  "love letter" is correspondence written between two lovers whereas the later means a letter expressing the love of other relationships such as siblings, friends etc.

You need to capitalize your "i"s when referring to yourself.  This the exception in capitalizing. 

Dear

Dear
　　Those word, "Dear", take me away to another time when we used to write to each other after mom and dad died.

I used to tell you about new friends and my new life. And you used to tell me about the grand time my mom and dad were having in heaven. Truth is nothing.

What you believe to be true is everything. And the main thing that i used to believe was that i would be with you forever. Forever.

The reason it has taken me so long to write to you is that i see that i have been a fool. I've spent my life fooling myself.

Ever letter i've ever written to you has been a love letter. How could they have been anything else!

I can see now that all of them, except this one, were bad love letters. Bad love letters beg for love back. Good love letters ask for nothing.

This, I'm pleased to announce is my first good love letter to you. Because there is noting more for you to do. You've already done everything.

I have enough of you in my head to last forever. So please don't ever worry about me. I'm peachy; i really am.

I have everything. If i had one wish, it would be that your life brings you a taste of the happiness you have brought to me, that you can feel what it's like to love.