The Weight of Secret Desires in a Long-Term Relationship

I’ve been married to my husband for seven years now. We met when we were both fresh out of nursing school, and I fell hard for his kind heart and intelligence. Over the years, we built our careers, bought a house together, and even started discussing retirement plans. On paper, everything looks perfect, but I've felt this gnawing emptiness lately that’s starting to wear on me. It all began last summer when he was working night shifts for several weeks. During his days off, I stayed at home alone while my friends from work came over after hours for socializing and sometimes just passing time in the quiet apartment. One such friend is Jane; we’ve known each other since nursing school. She’s a few years older than me but maintains a youthful spirit with her fiery personality. Jane would often stop by unexpectedly, and one evening, she caught me at a vulnerable moment, stressed from work, tired of household chores, longing for something more than what my marriage currently offers. We ended up talking late into the night about all our fantasies and desires that we rarely share with others. She brought up kinks I never knew existed inside of me, and before long, I found myself feeling a heat between us that hadn’t been there in years. One night, as my husband was working late again, Jane showed up unannounced at the door after our usual chat over drinks. We started laughing about old times, and suddenly, we were kissing, it wasn't planned but felt inevitable given the emotional connection we’d shared during our talks. It led to more than just a friendly hug, and I let myself feel things I hadn’t in what feels like an eternity. I haven't done anything since then, not wanting to break apart everything we’ve built together. But every day, as I think about the future, this emptiness becomes harder to ignore. Am I being unreasonable? Should I tell my husband and risk losing everything or just leave it as a secret that only Jane and I share? What would you do in my shoes?