My Hidden Fantasy

I'm a trans man in my early 30s who's been married to Sarah for five years. I've never told her about this one fantasy that keeps me up at night. It's not something we do together, but it's consuming me. Last week, when I was alone and feeling particularly restless, I found myself fantasizing about another man with a muscular build, the way his thick cock slid into me, stretching my hole as he pounded me hard against a wall. The roughness, the sweat, the sounds of our bodies colliding, it's all so intense in my mind. I feel ashamed and confused. Should I tell Sarah? Is this normal for someone like me to have these thoughts?