give it time and a good setup / fit. you did 10 miles on a road bike that wasn't set up for you and managed. the creo 2 is a MUCH comfier bike. i have faith.
also share these fit concerns with the shop and their fitter, they may recommend you size up a little for the higher stack / head tube, and then go with a shorter and more vertical stem. you also don't ever need to use the drops - personally i like the "aero hood" position where you bend your elbows as much as possible with your hands on the hoods for anything speedy except a really fast descent, where i do use the drops. but i bet on a 2 hour ride i'm in the drops for <5 min. the real beauty of the drop bars is the position it puts your hands and arms in for the majority of the ride, relatively aerodynamic, hands on the controls, good visibility, nimble steering, etc.