I tried all the other antidepressants and they made me very sick. Welbetrin was one that I tolerated for three months before it as well did not work for me.
I was crying and very fatigued at first and after about a month it worked better. It actually gave me energy and I felt I could keep going.
SO there was a ramp up time. It did get my mind going so the doc gave me a low dose of geodon which helped with that.
May be your in a transition time, give it a little time but should you start experiencing lots of anxiety talk to your doctor.