How to deal with insecurities about my looks.

I am insecure about my height, skin/hair issues ( skin spots, pimples, dark patches, stretch marks, cellulite on my butt and thighs and also getting few white hairs on my head ), bones/teeth ( they are thin and weak). All these issues i got because i didn't eat well.... i am underweight right now, i lived by drinking tea/coffee when i was depressed and didn't eat well. They might reduce if i start taking care of myself.... but i believe not fully.