Is it normal to have really low self esteem as a teenager?

So normal. So, So normal. I have a couple of friends who are heavier than average. They call themselves fat, but a) the word does not fit or describe them, in my opinion and b) the extra weight does not make them less attractive at all. So I would guess that people are just acknowledging that you are not twig skinny, but "fat" and its associated meaning do not describe how they see you. I don't know what you look like, but I used to have the same insecurity and it helped to make faces in the mirror where I looked good, so I could point out my good features and internalize an image of myself that was pretty.
And don't worry about dating and stuff, I think being liked initially is 9/10ths of the battle in terms of being attractive/looking good enough to date.

u should try to do a lil exercise every day to help ur depression.. Sun bathing is another thing helpful. Lie in the sunlight until u can feel the warmth on ur skin. Tell mother earth u appreciate her. Sounds kooky maybe but it will help, I promise!

Women and girls can adjust to that. There must be on-line support groups. In the meantime, read trashy romance novels.