Dear Sherlock,
You will never read this, I know, but I need to tell you how I feel. I have been hiding my feelings for so long and I have always wished I could tell someone, especially you. And now I can.
Of course I loved you, Sherlock. Anyone in the world would see it but you. I regret every day that I lived with you by my side without my love, and always have. I don't know how you can suggest I don't live my life without you because I can't. I don't know what I'd be without you.
And now you're gone, and my life is meaningless. But I carry on, for you. Because I know what you want, you didn't need to tell me, and I will carry out your final wishes until the day I die.
I never told you that I cared so much about you. You lived your life in ignorance of my feelings and you lived a miserable life. Sometimes, I think, if I had told you, I could have stopped you. But now is too late for speculation. Now is too late for everything.
I never believed what you said, and what Anderson said and everything. How could anyone who knew you even the slightest bit? And now you're gone, gone forever.
The world will never be the same without you,
John