Use $_SERVER['REQUEST_URI'] instead of get_permalink() to grab the current URL. get_permalink will give you the full address of the current post, not the address of the URL visited.
e.g. for example.com/test/page echo $_SERVER['REQUEST_URI']; prints /test/page
Note that this doesn’t include the hashtag, as that part never gets sent to the server, and it also doesn’t include ?foo=bar type parameters, those are in the $_GET array.