I wish I was thick!😤😔 insecurities!

I've been thin my whole entire life. I'm not bony or anything I love food so much and eat 3 times a day it's just I'm so tiny and it's really hard for me to put on weight.  I am only 4'9. I have boobs but I wish they were a little more bigger my butt isn't super flat but I wish it was more rounder and fuller with bigger legs. I hate the fact that I always have to compare myself to these fitness models on social media and some other females. I wish I can love my body just as much as my boyfriend does. I just get so insecure about myself and depressed that I get scared that he will find someone way better then me which I know deep down in my heart he won't he loves me and I've been with him for a year already and I love him very much. I get frustrated with myself knowing that's not going to happen he dated a few thick girls that's why sometimes I think I'm not good enough 😪  it happened to me in the past plenty of times with other guys that I've dated before that's why I feel like this sometimes and it needs to stop. A lot of girls find him attractive that's why but I know deep down I'm the only girl he wants. I'm just VERY insecure about my body and I can't find any features about me that I love except my face and my hair. It's just my body that I can't stand. Yes I workout then and there but there's a very little difference. I need to stop feeling like this but it's just so hard and I don't want it to affect my relationship 😔