I'm sure this has been covered and I apologize if it has a simple fix. I log in through Facebook but my user name is a string of numbers, no pic, can't add my friends, or share music/play lists. The best I've seen trying to search an answer is mods looking into the situation. I already tried logging out and back in, reinstalling etc. Y'know, the usual advice.
It looks like the link between your Spotify and Facebook accounts has been broken somehow which is why you are seeing that number as your username. If you could get in touch with the support team directly using the online contact form they will be able to work some magic to get it back to normal for you.
If you get an automated email reply back directing you to the community or help pages, you need to reply directly to that email (even if its from no-reply) and one of the customer services agents will get back to you as soon as possible.