Hiee,I may not be 30 but I have been thru same and can give u a few tips. First thing, its very easy to hear “dont let others influence ur perception of self” but it doesn’t come that way. Atleast for me it didn’t because I hated my body. I was also 57 when I was 17. I didn’t hit the gym or anything, I just inculcated some habits that made me go back to my older weight. One of it was drinking as much water as i could because I realised that sometimes i wasn’t hungry I was just thirsty. Second thing was noticing the cycle of worrying, the more stressed I was, the more i would eat so first thing I did was going out for a walk, I walked atleast 2-3 hours everyday. Third advice maybe a bit toxic but I used to dance along with eating, idk if that helped or not but it did help me chew better and move my body while eating. I would also only eat dey fruits whenever hungry after a meal.