Unfortunately, the script you are using will not work at all, because of changes to the Kindle firmware which basically blocks the method used.
There is, however, a different method that will, provided you can obtain copies of your books via a compatible computing platform's reading software.
We can't link to or discuss in detail the usage of any DRM-circumvention tools, for the protection of the MR site, just in case someone decides to send lawyers over. Google remains your friend, especially if you modify the search terms.
