Working Nights and Secret Kinks

I've been working the night shift at a warehouse for over two years now. The long hours leave me feeling drained, but it's the only job that fits my schedule since I have to be home during the day to take care of my mom who can't manage on her own anymore. My partner, Jane, is great about taking care of things when she's not at work herself, and we talk a lot about our feelings for each other every night before bed. But there's this thing that I've been keeping from Jane because I know how much she hates it, this kink of mine. See, something about the darkness, about being alone in my thoughts late into the night, makes me crave a certain kind of... intensity. I'll find myself searching through the darkest corners of the internet, looking at images and videos that speak to this desire for domination, power exchange. It's like there's another side of me waiting to emerge as soon as everyone else goes to sleep. Jane is very loving and open about her desires in bed; we communicate a lot when it comes to sex, and I love making her feel good. But she's not into any kind of role-play that isn't soft and cuddly. She tells me how much she loves the way I make her feel safe and cared for, like we're sharing some secret intimacy nobody else can see. So here’s my problem: I'm torn between keeping this side of myself hidden away because it scares me to think about what Jane might say if she knew or telling her and risking everything. What should I do? Am I being too selfish by indulging in something that's not part of our relationship? Is there a way for both of us to explore this without hurting each other?