Meeting a guy today, nervous & shy?!?

Basically i know this guy, his friends and my friends hang out together but we have never met. We have been speaking for a few weeks and i am going to see him today. Here is the problem; i am a very shy person. I am not very confident because i am fat and not that pretty (size 14). I am scared he will not "like me" because of how i look. He is 3 years older, and very attractive. (I am 18). He has saw a couple of pictures of me, but i think i must look better in pictures lol (no i dont edit them!!) haha! Anyway does anyone have any tips for meeting him? Any advice would be welcome! Thanks a lot! :) x