How difficult is the switch from flat to drop bar?
I have never had professional fitting - just adjusted until it felt right.  I am sure a professional fitting would be nice but I just did not want to spend my money on one. 

A road bike might not be the best bike for you.  In a drop bar consider cyclocoss or light touring.  Some companies have a drop bar "commuter".  They are going to have bigger tires and a bit more upright position.  If no other bike feels comfortable then stay with you flat bars.

As far as get used to it just ride. Brakes and gears are different but clearly you have figured that out.  More hand position.  Most riding is up on the brakes/hoods.  If you get on the bike and go straight down in the drops it will feel low - that is for high speed and into the wind.