Did I give mixed signals, or did she?

I could use some outside perspectives because I can’t stop thinking about this. I feel completely blindsided and I’m unsure if I was misreading the signals or if she genuinely sent them my way. I work closely with a female colleague, and over time, it seemed like we built a special connection. She confides in me about personal matters that she doesn't share with anyone else—little things like her nail art, her socks, her notebooks, and even random purchases. Initially, I didn’t think much of it, but as these moments accumulated, I started to feel like I was more than just another coworker to her. We chat frequently at work—more than she does with anyone else. She laughs at my jokes, playfully teases me, and appears truly at ease around me. She has also shared some deep personal stories that she rarely discusses with other colleagues, which made me feel like our bond was significant. Eventually, I found myself contemplating the possibility of something more. At first, I wasn’t viewing her in a romantic light, but her behavior gradually made me wonder if there was potential for a deeper connection. For instance: She once mentioned wanting to see a movie on a Friday but expressed uncertainty about who she should go with—interestingly enough, it was Valentine's Day. My friends thought she might have been hinting at something, but I was uncertain. She repeatedly emphasized that she’s single, even when the topic didn’t involve relationships. That led me to think she might be giving me an opportunity to ask her out or at least gauge my interest. However, since we’re coworkers, I was reluctant to create any tension. Instead, I tried to feel things out in a subtle way. I made comments like, “I’m new here; you should show me around,” but her response was neutral. Then, out of the blue, she dropped a bombshell on me. During a light-hearted chat, she suddenly said, “This is confidential, but I’m seeing someone.” I was taken aback. I maintained my composure on the surface, but inside, I was in shock, bewildered, and completely caught off guard. I tried to play it cool, but I could hardly maintain eye contact. Now I feel as though I’ve lost a chance to be with her. I can’t tell if I misinterpreted everything or if she was genuinely giving mixed signals. And to make matters worse, I have to see her every day at work. I’m uncertain about how to behave around her now. Should I act natural and just keep it friendly? Or do I need to emotionally distance myself to avoid these feelings? Did I inaccurately fabricate the whole situation, or was she somewhat leading me on? I really need some honest feedback—was this all in my head, or did she actually toy with my emotions?