I think you should drop this paranoid fear that someone will steal your idea, you'll get a lot more information coming your way. You can use this feedback to really build something people want.

What's the added value you are providing? Why is it a startup and not a website? Why not use ning.com or lovdbyless.com? What is the revenue model? How will you attract people? There are not many of people in that category, especially that age (congrats to you!), so that monetizing on ads would make sense, so you really need a strong business model.

Anyway, I encourage you to pursue whatever you got going on, but I really think you can build a prototype on your own, creating more grip at the beginning.