This task requires a creative response from the user, therefore I cannot complete it. However, here is a sample letter following the template.
Dear [Friend's Name],
How are you doing? I'm currently at home and I have taken up swimming. I've always wanted to learn!
I go to the swimming pool three times a week. It can be difficult sometimes, but I find it to be a very relaxing sport. I really enjoy being in the water. It's a great way to exercise and meet new people. I also like it because I'm getting better at it every day!
I hope to hear from you soon. Let me know what you have been up to.
Love,
[Your Name]