I think there's more possibility of it being linked to the prozac, or it is a combination of both. The timing is almost exactly the timing when an SSRI starts to "work". Also, the initial three weeks where you felt ok, the prozac would have been doing nothing, which makes me think you were naturally recovering.
I would strongly suggest going med free and seeing where your baseline is (Speak to your doctor, of course). I am absolutely baffled as to why they put you on such a medication after one week of anxiety, unless you were already suffering from that before the trip?