Husband thyroid/anxiety.. help!!!!

My husband recently had surgery (May 2007) to remove his thyroid and 2 parathyroids.  Before this, he was being treated for depression/anxiety.  He was on 200mg of Zoloft and xanex as needed.  Before the surgery his anxiety was not too bad, since the surgery, he anxiety is so bad that he attempts to go out to eat, or drive to work, and gets panic attacks.  He is taking Levoxyl as well.  He is very fatigued and his doc keeps saying his blood work is fine.  We have a family, and his anxiety is so severe that he gets really nervous about doing anything so he would rather stay at home.  Could the Levoxyl be causing this?  He has been on Zoloft for about 3 years now.  He is popping Xanex almost on a daily basis now.  I am at a loss of what to do because he says he just simply does not feel well.