Prom: the bad conversation (vent?)

So basically at my prom table it was my friend kaitlyn, my ex(D), someone I hate and their friend. I had some good conversation with D which suprised me but at the end of the night he wanted to talk to me so we talked. He cleared the air for himself but I decided to admit "I still felt chemistry tonight to him" but shortly after he kinda said "Goobye, have a nice life" and maybe even gave me a thumbs up ?? I felt sparks and Feelings coming back/ creeping back in so that made me really upset and ruined my night. Not only that, he decided to keep in touch with my friend but didn't even consider with me. I do not get why and feel like i did something wrong or something ?? Regardless,I'm feeling feelings rn. Do I try to get in contact with him or leave him be? Does he not want to have me around? Did I scare him away? So many thoughts are going through my mind tbh. I wonder if me mentioning my bpd scared him away. It's a million thoughts a minute tbh. I wish I could tell him how much I missed him, how I'd do it all again , how i wish i didn't ruin things and stuff like that. It's been years yet I've been crying over him since last night because I really thought maybe just maybe we would give us another try. I'd always choose him if I had a choice to choose anyone. I think I'll always have feelings for him, but he might not even like guys too. We dated back when I was a cishet girl. I just don't know

UPDATE: THE FEELING WAS FRIENDSHIP /REF 
BASICALLY PRETTY SURE THEY WERE PLATONIC BC I HAVE FEELINGS FOR SOMEONE ELSE THAT R NJBSFNKJFKF