Dropped 20mg in one day

Hello! My doctor is having my switch from 60mg to 40mg in just one night. He said that I can rotate 60mg and 40mg every other night if I get withdrawals. I am seeing a lot of scary information about only dropping 5 percent of the dosage over the course of weeks. Im having some intense mood swings today, it's day two, so I'm pretty nervous that maybe my doctor doesn't know that cymbalta needs a gradual change? Has anyone else had this experience?