Please brace yourself this is going to be a long rant. I can't share this with my friends and I have to get this out of my mind.

There is this girl who had a crush on me in school. She even expressed that in school but at that time I was already dating some other girl and I rejected her. Let's just say things weren't all good b/w me and this girl for the remaining time period of the school. I was being a jerk to her because by then gf told me to do so. Now 5 years later she followed me on Instagram and we started talking again. It's was just normal stuff and I apologised for how I treated her in high school and told her that I broke up with the girl from school. She was a lil salty about it saying "you should regret it" when I said I regret I dated that girl in school. We chatted for a few days with me casually flirting with her now and then. She was laughing at all my jokes and she seemed interested. One day I casually told her "I'm having a lil crush on you rn idk why" She responded with laughing emoji times 10 and a 'omg'. I said something and she responded with some stupid shit and I said 'ok that's -2 from crush points'. She saw it but never replied back. After 3-4 days I again texted her for some help with artwork(she's an art student) she asked me questions about it I made a few silly jokes and she laughed as always and suddenly out of now where she seenzoned me. Never heard from her since. Idk what went wrong but I'm glad I atleast tried, I really liked her after I got to know her a little more.

What are your thoughts about this? Should I just forget her for good?