Welcome to the hell. Quite a few people have had this same issue since earlier this week. The only thing we can figure is try to log in during non peak hours. That seems to sometimes work, I actually got in for a few hours yesterday at 1 AM.

SE will tell you its your problem, which is a load of BS as I can play everything else just fine. So it's probably not worth your time to try to contact them. I am HOPING that they fix it in the upcoming maintenance.