I’m not sure that body positivity works for everyone. It may well be that some people never learn to love the body in the mirror. I’m speaking to those people now:
You don’t like how you look. You wish you looked different, that your face and figure pleased you.
It’s sad. It’s unfortunate that your appearance brings you pain. It’s not shallow, or vain, and you don’t need to outgrow it or brush it off – it’s a legitimate suffering.
And someone who’s suffering, you can feel sympathy for. Even love.
You don’t have to love the body in the mirror, if that doesn’t work for you. But do try to love the person in the mirror who doesn’t love their body.