Are models just naturally thin or starving?

They are both.

I am naturally thinner than most, but I'm still a starving wreck. I blame no one but myself and my choice of occupation.

When I first started modeling, I was 15 years old. I weighed 92 pounds at 4'10" (I'm a petite model).

This is what I was told by the agency after the first round of interviews: "You need to lose at least 10 pounds."

I did. I exercised and starved. I continued to go to school and spent all my time studying or exercising - anything to not eat.
My parents were proud. I was "fashionably thin" and I scored very well in my exams.
I was anorexic and constantly suicidal, but seeing the proud faces of my parents, I could not let them down. I know they love me only because I'm a perfectionist.

I am now 18 years old and still 4'10". I weigh 85 pounds.

"Naturally thin" is not enough nowadays, even for a model. The competition in this field is tough.