Hmmm... 18, yeah she may just be shallow.
I don't know, I think it was a date. People generally don't go online to make friends, especially when they're talking to a member of the opposite sex. It sounded like she was interested in him to start. The part where he says something about not wanting to be with women who care about looks may have made it seem like he was getting ahead of himself. She may have thought "What are you talking about? We're not together yet." Or she may have been put off because she's a shallow 18 year old who cares about looks haha.
Anyways nukl92, don't dwell on it too much. Just learn from this experience and go meet someone else. And stop being so self conscious. Either accept how you look or go to the gym and get in shape. Because when you find a girl who really likes you there's going to come a point where she's going to want to see you with your shirt off ;)