A dear friend of mine is getting married in a couple of weeks. She's such a extrovert person, always ready to party. Above all she loves dancing.
On the other hand, I'm the exact opposite. I don't feel comfortable when dancing, because I don't like my body, I don't like the way my body moves, I don't want people looking at me. Dancing in public makes me feel weird and ugly.

The problem:
Every now and then (and more and more now that we're getting closer to the wedding) she says things like "Oh, I would love if all my friends danced that day!", then she looks at me like "I'm obviusly talking to you, life is short, enjoy it! :)"

So, I know she cares a lot and don't want let her down, especially on her wedding day, but I'm afraid I'll feel awful if I actually get on the dance floor. What should I do?

Additional informations:

• It's not I don't dance at all. I do dance, but only when I'm alone.
• I really hate the kind of music my friend listen to (aka the music she chose for the wedding party).
• I've already tried dancing at other weddings, because I'm tired of being the way I am, the different one, the one who sits at the table while everyone else is getting fun, but every time I did it I later regretted it.