There are a few things you can do to prevent this in the future. Next time to encounter a ghost queue, restart your client a few times and you should be able to see the queue again. Also, double check your account details before you log in. Make sure they are correct, you can also use the "Remember password" button so you don't have to enter your password every time you play.
With the loading maps issue this could either be down to poor internet connection or server lag, I recommend waiting 5 or 10 minutes before restarting your client.