Pain when breathing in my esophagus

The last few days I've had pain every time I breath in my esophagus. Wondering if this is caused from Effexor I'm on. It started about two weeks after raising the dose from 75mg to 150mg. Went to doctor today but she didn't know if it was from the meds, so she put me on 75 mg again. There's no pain with eating or drinking. So don't know what to make of this situation.