I really want to tell goodbye to a guy that I love... and like... ( he is straight)

He doesn't know my feelings for him or that the thing I'm gay.... What PM should I sent him / or e-mail, to make him understand that is better for me to say goodbye (I want to give up and not hurt myself with dreams).

I don't want to tell him in a direct way that I'm gay. If there is a word game and also a little riddle it would be perfect XD.

Thanks (Just can't find my words)