I wrote him a letter telling him how much I like him. Should I send it? I dont know what to do.

I met this guy at a gym that I workout at a about 6 months ago and lately we became good friends. I had a crush on him from the moment I saw him and we became friends, my feelings grew more intensely. Recently we spent an evening together, dinner and a movie, and a chance to talk about a lot things. He talks constantly about girls and feelings for them. He doesn’t know that I am bisexual. I thought I was going to have the courage to tell him, but I didn’t. I haven;t been able to sleep well for the past week..thinkin of him.
I don’t to complicate his life…but I can’t forget about him either. I know, based on what he says, that he’s only into girls.