Here is what I suggest:

1) First take a piece of blank paper and just write words that come up as you think about the letter you will write. Do not put them in any order or structure - just write what word pops into your mind freestyle.

2) After a short break, take those words and write a first letter to T. This will NOT be the one you send. Write freely all the things you want to say to T and use your paper from the first step to help you. You can even scratch off the words on the first paper as you use them in this letter. When you are done, set the letter aside for at least 24 hours.

3) Now take the letter out and read through it. Use this as a guide to help you write the final letter that you will send.

Good luck!