Well I would have to see both of you to be able to give you an informed answer. But I do think falling in love with a girl is more about her personality than her looks. Looks might get her foot in the door, but personality is what ultimately makes you love a person. So I don't mean any disrespect, but it's possible that she just has a better personality than you, and it's the kind that men really go for.
It's also possible that you have a more sexed up look than she does. I'm not quite sure what you mean by "hot." To me, "hot" just means a really good looking girl, but if by "hot," you mean someone who looks sexy as opposed to beautiful, then that could be it too. Maybe guys just look at you and see a sex object, whereas in her they see a sweet, beautiful girl. I think the guys who would do that are probably shallow and not worth your time, though. Like I said, looks might get your foot in the door, but ultimately, personality should matter, so if a guy is worth your time, he would eventually get to know your personality and that would make more difference than how your body looked. That's how it would be for me, and I can't imagine only thinking of a woman as a sex toy solely because of how she looked.
It might also be that you're just not as hot as you think you are. Again, I mean no disrespect, but you haven't shown a picture, and I've known quite a few women who claimed to be hot over the Internet, and then once you got their picture, they were just plain looking, or even borderline ugly. If you've done modeling, I could be wrong, but it also depends on what kind of modeling you've done. Not all models or celebrities are attractive. I personally never thought Jessica Alba was good looking, and she always looked to me like the kind of girl who if I did know her in real life and I were attracted to her, it would be because I liked her personality. I never found her body all that desirable.
Those are just a few possibilities. I think you should really show pics of both you and your friend for a better answer.