I don't think sexuality defines a person. It's one small part of who you are, in my view. You are many things, and I never felt that people were defined by their sexuality solely.
Great people do things before they're ready. They do things before they know they can do it. Doing what you're afraid of, getting out of your comfort zone, taking risks like that - that is what life is. You might be really good. You might find out something about yourself that's really special and if you're not good, who cares? You tried something. Now you know something about yourself.