Using lorien(prozak) and serlife(zoloft) at the same time

I have been on Lorien 20mg for the past 5 years in order to treat depression.  For the last 2 years I've been using zopax 0,5 mg as well for occasional anxiety disorders.  For the last few months I was using zopax on a daily basis and started to see a psychologist. About 3 weeks ago I suffered a severe panic attack and consulted my GP again. He prescribed serlife(zoloft) for the depression and the anxiety disorder.  He also told me to continue taking lorien(prozak) until the serlife(zoloft) starts to take effect.  I still use zopax (half a tablet daily) whenever I'm feeling anxious.

I've been on the Serlife(Zoloft) for the past 18 days and still can't lead a normal productive life.  Am I too impatient?