I was Pressured into Impregnating my Sister-in-law

I was pressured into impregnating my sister-in-law when I was 17. because my brother was left sterile from a tumour on his nutsack, and his wife wanted children. She would come into my room at night and sit on top of me, but I wasn’t allowed to touch her. Now that I’m a father, it really bothers me to hear my child call my brother daddy. It actually feels like a stab in the chest, and I want to tell my wife, but I know I can’t. Don’t think I’m lying because it’s the truth, and I’m willing to prove it by all means possible.