I've been riding for, well, decades. I can tell you that it's never an easy time period between before the bike arrives, and after you've ridden it for the first month (it usually takes that long to tweak the bike to fit you perfectly). We all go through doubts until... that perfect ride. That's the ride that comes once your body becomes adjusted to the new riding position, and any other little adjustments needed. That's the ride where you find that you CAN make it up that hill easily with the new bike, or that riding can be totally pain-free.

Recently, I decided to get a new geared road bike. After doing research and testing many bikes, I went for a bike that I found to be very comfortable and fast; a Blue Competition RC6. I'm in love with this bike, but that's what worked for me, and everyone is very different. Did I have doubts? You betcha. I rode the Blue for the first few weeks with a "too-long" stem and "too-wide" handlebars. I knew that theoretically, once I switched these components out to the ones that fit, that my shoulder pain "should" go away. However it wasn't until I actually switched the handlebars and stem, and the pain ACTUALLY went away that I was sure I'd made the right decision. Until then, yeah, I was nervous. And I'd been through this many times before. I just did my first century on it, and I can honestly say that it was the most comfortable century I've ever had.

Also, going from hybrid to road position takes time; time for your muscles (and mind) to adjust to riding in a different position, and different style of riding. Depending on how often you ride, that will take a month or two, but afterwards, you might actually find the road bike more stable a high speeds than the hybrid.
Congratulations, and don't worry. You've been very smart about the way gone about picking out your new bike. I'm sure you'll love it.