If you want to try something else, just let your doctor know. If he refuses, get a new doctor.
About two weeks is as long as most people need to see if a med such as this is going to help or not. I need about 5 days at most.
Cymbalta does not make me anxious in near the same way pristiq does. Effexor and pristiq lead to a more aggressive nervousness than cymbalta does in myself although it still does increase my irritability to an extent.
Just today I decided to try just cymbalta for awhile (stopped my 30mg lexapro today). I am sick of the flatness I feel from lexapro.