Dear Sherlock,
I'm so sorry, so sorry that this had to happen. It's just not fair, why did it have to be you? Out of everyone, it was you and you left me and I won't ever forgive you for that even though it was never your fault. But I also thank you, thank you so much for being my friend. Since the beginning you had changed me, made me a better person. Our friendship, relationship, was the most life-changing thing that could have ever happened to me, and to you as well I know even though you aren't here to tell me that. But, thank you so much.
Always.
-John