(Vent) Could this be limerence over a stranger?

Assalamualaikum, I'm 18F and still figuring a lot out. I grew up mostly secular but started reconnecting with my faith around 12–13 after moving to my dad's country. I've generally been careful around men because of past trauma and other stuff, so romantic interest hasn't come easy. Growing up I never felt pretty and got bullied for being quiet and having acne. In my small hometown in the US everyone seemed to be dating in elementary school, and I was an easy target for creeps - adults around me didn't do much about it, so I ended up pretty wary and kind of closed off. When I started middle school it got harder. I wore hijab and stuck out as one of the few white-passing girls doing so. People stared and asked questions. At school I was put into a Pre-Med elective and there was this one guy - I think he wasn't Muslim like most there. He asked me out once, and while I said no he didn't push me and he respected my boundaries. He was conventionally attractive and kind, and I never had contact with him after. Since then, every now and then my mind fixates on him. I write whole what-if stories in my head about what might've happened if I said yes. Other guys in my past chased me or got upset when I wasn't interested, and older guys harassed me when I was young, which only made me retreat more. I never felt a real crush before him, so I don't get why he keeps popping up and why I replay things so much. Is this limerence? Or just longing for something I never had? JazakAllah khair for listening - I hope this makes sense.