Hi,
It's been my experience that if you really want to continue dancing, losing your partner isn't the end of the world. I've had four partners in the couple of years or so I've been competing. Personally, I think that the more people you dance with the better. Not only can it be more fun (you get to meet more people!), it definitely improves your dancing. Don't get me wrong - it can be discouraging when you realize that you have a hard time leading anything more than basic figures! Think of it this way - it was tough when you first started lessons, wasn't it? It'll be tough again - but knowing that not only can you dance, but dance with anyone, will be just as rewarding.
Ballroom dancers tend to be very accommodating people. Unless you're flat-out reckless, most people will be happy to help you practice your leading on the social floor. So, have fun, practice leading, and remember that dance is a language - once you speak it, you'll always have someone to talk to.
Good luck, and happy dancing!
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--Eric