I don't think I've read every post from the past few weeks leading up to this med change, so please forgive me if I ask or say something that has already been said.

SSRIs do seem to have slightly different side effect profiles and like all meds different people will get a different set, some of the things you mention are hard to define which they are of side effects or symptoms of depression. With your pain issues has anyone suggested duloxetine? it's a slightly different anti depressant type which evidence suggests helps some types of pain.

I've had three periods of major depression, always involving psychiatrists and only one avoiding hospital admission. This means I've seen things from a different perspective and enough evidence from friends about a slightly different approach from GPs. GPs seem to try more SSRIs, whereas every time with the psychiatrist they'll start with one and if that doesn't seem to have an effect they'll try one other SSRI before looking into alternatives or augmentation. I think what I'm trying to say is if sertaline doesn't work then you might want to ask for a non SSRI antidepressant.

Hope the switch works and that you don't have to deal with typical early sertaline problems (nausea).