Both Pristiq and wellbutrin are stimulating antidepressants, and aren't usually first choices if anxiety is the main problem. If depression is the main problem, that's a whole different story. I'd try a different ssri, because if it's the serotonin reuptake inhibition itself that's causing the problem, Pristiq does that as well, but it also acts on norepinephrine, a stimulating neurotransmitter.