Hiding My Secret from Him

I'm a high school teacher and I've been struggling with something big. It's hard to explain how lonely I feel despite being married for years now. Sometimes, when the stress of teaching gets too much, my mind wanders off into dark fantasies. Last night, after another exhausting day full of grading papers and dealing with unruly students, it happened again. I found myself thinking about that new student, Alex, a senior who always seems so confident yet has this air of vulnerability around him. He's in his twenties, but still one of my kids. There was this moment where we were alone in the classroom after school ended, and he looked at me with those piercing eyes that I couldn't help but stare back into. It felt like there was something unsaid between us, just a fleeting second of connection before reality set in. That's when it all started to unravel inside my head, fantasies about what could've been if we had let things go further than a teacher-student relationship. But then the guilt hit me hard, I'm married with responsibilities and this is purely unethical. It's not like I acted on these thoughts though, but the thought of them still keeps me up at night.