I need advice please.

[AllenJoel22]

I'm 17 in High School and I'm pretty open with my sexuality. So I've always had a crush on this one kid. He's in my grade. Around last year, last summer he texted me on a TextNow Number (its an app you can use to text people on your iPhone and it hides your number and makes a new one) and he basically texted me saying all of this stuff about how he liked me and how he needed advice. We were texting for a couple hours, maybe like 3? I ended up finding out it was him and I really didn't know what to do. At first I was a little embarrassed and I was extremely confused because he has a girlfriend (and still does to this day) and I couldn't tell if it was a joke or if he was serious. In my freshman and sophomore year I always acted like I hated him because I was still closeted and he was sort of my first guy crush. He always wondered why I hated him and he was the only person who I made it obvious that I didn't like, even though it was really the exact opposite. I guess what I'm really trying to ask is what do I do? I never can get him off of my mind, and whenever I actually do there's something that makes me like him again, even just making eye contact with him in a public place or at school. Its been over a year since the incident has happened and I feel like I should just get over it. Am I falling in love? Or whats even going on... we never talk so I don't get why I have these feelings.