Have you seen a psychiatrist? You're probably getting "rebound" anxiety from the xanax (klonopin would be more long-lasting), and you could probably use an anti-depressant to get into your system to control the anxiety. The anti-anxiety drugs are so addictive....
I had uncontrollable anxiety, too, but it lifted about 4 days post-removal. My doctor suspects the IUD put me over the edge-as my EEG showed abnormal brain waves that were most likely the direct cause of the 7 week long anxiety attack. You may have an anxiety disorder that the Mirena complicated.
I am so sorry to hear you haven't gotten any relief. I know how the long the 7 weeks were that I had it, so I can only imagine that you're barely hanging on.