Unfortunately, it looks like Xanga is gone and there is no way to recover anything. Both their twitter and facebook look like they've been abandoned too.

Anyways, you can put your xanga url into archive.org (wayback machine) and may possibly be able to access an archive of your blog by that site. Just copy and paste your blog entries into a document if they have it archived. Outside of that, there is no way to "recover" your blog anymore.