This was probably just meant as a complement but I can't stop hating it

I went to prom as friends with a close friend last week, and it was really fun, but I can't stop thinking about something he said. For context, I've been the token "tiny girl" for my whole life, called twig and such at family events forever and all that shit, and I hate it. I hate being flatter than a crepe, and I hate that no matter what I do, I just can't be who people find pretty. I know I should be grateful for this, grateful I never have to diet, but I just can't stop hating it. To get back to the story, I wore a dress I thought was really nice, and all he had to say about it was "that dress makes you look really thin", that's it, not "it looks nice!" or nothing, just you look really thin in that dress, he wasn't even the only one who said it! 4 differnt people told be that, with that stupid, codensatingly sweet voice that justs gnaws on my brain. I'm sure they meant it as a compliment, but it just sucks. I hate this, and every time I start thinking I look good, I see everyone else, with the perfect curves, and the idolized bodies, then there's just me and my stupid door frame body. It just sucks more because I do work out, and I eat the right things, and I wear the right clothes, but I just can't be pretty, no matter how hard I try. This is probably just stupid, but this has been driving me insane for the past week.