Co-sign everything written above! The ladies of GC give great advice!
Going through recruitment could be a wonderful way to boost your communication skills and help you conquer your shyness - especially if you remember not to label yourself as "the shy girl", as everyone else has said. And, during recruitment, if you get nervous about talking to a sorority member, just remember that she's probably just as nervous as you! Recruitment is a two way street - we are just as eager to impress the PNMs as you are to make a good impression on us!
Secondly, there is always room for a "shy" girl in any sorority. Every group needs to be made up of diverse personalities; not everyone can be the outgoing cheerleader type, and that is perfectly okay, especially in a sorority. It takes many types of people to make a chapter run smoothly - leaders, supporters, girls who like to talk, girls who like to listen, etc. I have a feeling that someone as thoughtful and sensitive as you seem to be would be an asset to any chapter!
Additionally, you clearly realize the competitiveness of recruitment at UF, and it seems as if your friend has done a great job of preparing you for the realities of rushing - i.e. the possibility of being cut, etc. It seems that being aware of what
could happen but keeping a positive attitude is the best policy. But I'm not the first to say that.
Best of luck with your decision!