I look too young for my age!

I’m a 23 year old woman, i recently got out of a relationship a few months ago and back on the dating world. I’ve always been skinny but this summer i lost a lot of weight due to health problems(recurring panic attacks) 54kg to45kg and i’m already short 5’3 so it’s making me look a lot thinner and eventually alot younger, the remarks people have been making on me lately are quite hurtful especially those who know me(like there’s something wrong with me)i usually don’t care but it only became an issue when i realised men were avoiding me because of it. (I’m still an attractive girl though with a pretty face and a sense of fashion). I’ve been on quite a few dates lately while online dating, and once they see me i get alot of judgements like( you look younger than in pictures are you sure you’re 23!?), or this one guy even drove off once he saw me from his car window and it never made sense until now, i thought he was just some rude jerk. Another guy was basicaly put off by my weight since they prefer curvy women and they all basicaly never call back or ask for a second date no matter how great the 1st one was..
It was all so weird and i started wondering what’s going on, i would always be the one to start conversation, but i stopped doing that altogether only to realise no one cared to initiate himself.
Until lately this guy i gave my number to at an exhibition, finally texted and was like (oh you’re so beautiful, but you sure you’re 23 you look 16!!!!.. and it finally hit me! Like this is it this is why men have been avoiding me all this time(i usually date older guys 25-30), they probably think i’m a minor and would rather be with someone who looks older and has more attractive body assets.
Has anyone been through this before and please tell me what i should do since i’m looking for a serious long term relationship?!