whats what?

I am weaning off Effexor and quit after one wk at 37.5mg.  I ended up in the ER with a MAJOR panic attack.  I am having all of the side effects, dizziness, flu-like symptoms also.  When I began weaning from 225mg Effexor I began 20mg of Prozac which I had taken several years ago.  I was 3 weeks into the prozac when all of these symptoms came on.  Does that mean that the Prozac isnt working bc I had such a big panic attack.  I have had 3 in the last 3 days and am living in fear of the next one.  Is it the Effexor withdrawl (withdrawal)?  Is the Prozac not working?  I am also on 200mg Lamictal.  I do not think that I am bipolar.  Doc said that the panic attacks may be manic symptoms and so she told me to take zyprexa 2.5mg at night, stop the prozac and take 37.5 of effexor until she gets back in town.  She told me that she thinks that I am bipolar but I don’t understand why.  She said that she thought my panic attacks were manic episodes that manifest as irritability and panic.  I don’t get it.  I do have ups and downs but just like anyone else I think.  I have always done well with just an antidepressant but they always seem to poop out after a couple of years and that is why she put me on the lamictal.  She said that “poop out” could be another sign of bipolar.  Could the Lamictal be causing any of these problems.  Please help.  Im lost here!