I've always been taught in my Psychopathology and Psychopharmacology classes (I'm one of those--drawn to the Psychology field, fascinated by moods and disorders and then diagnosed with a disorder myself later) that antidepressants without a mood stabilizer can make BP patients manic. You should also slowly come off medications; you should never suddenly stop a medication (or drug when detoxing).

I don't know what the protocol is in Australia, but have you ever looked into going to a psychiatric hospital (if you feel that you are getting worse)? I went to the hospital a few months ago for "Postpartum Depression". They stabilized me (or so they thought, because they put me on Zoloft, which sent me flying) and when I was discharged, the social worker who was working my case was required to set me up with a psychiatrist appointment 2 weeks after my discharge to check in on my medication and to give me another prescription. This is how I got my proper diagnosis of Bipolar Disorder and we are now riding the medication merry-go-round to find the right ones for me.