Caryl,
The metalic taste can happen when the facial nerve is tramatized by AN treatment. I had this for 2 or 3 months after AN surgery. And it eventually went away. If you do a search for Metalic on this forum, you'll find a few past threads on it.
The balance thing that you mentioned also sounds like some post treatment AN swelling and pressing on nearby nerves. I know in some cases, CK patients have received steroid treatment for a while to lessen swelling symptoms. Steroids are powerful meds that come with side affects, so talk this over with your doctor carefully. As Steve mentioned, keep your doctor informed about any symptoms that show up. From reading CK patient experiences, the 3 to 6 month time frame post treatement can be prime time for odd symptoms. But they usually resolve themselves. Hopefully yours will resolve soon.
Regards,
Rob