Need advice

There is this guy I really like and I just found out that he is engaged. I heard that if you write a letter to him that tells him how you feel, it will help to let go of the feelings you have for him. I wrote the letter, I just don't know whether or not I should give it to him. I work with him and I don't want things to be awkward, but I don't want to keep everything bottled up inside. Does anyone have any advice on what I should do?