Only you can decide what's comfortable for you. That said, I "outgrew" my Trek FX (nice bike btw) in about a month, and sold it to a co-worker for a significant loss to get a road bike. I'm wondering if you know anyone who has a FXish bike, or even a cruiser type, you can borrow for a couple weeks, just to get going, build your confidence, and then make a decision. You might even be able to find a cheap one on Craig's List. Better than investing in a road bike you're too afraid to ride.

Oh....and welcome!