Can't login to any server except Frostmourne which I do not play on

Hello, so, I had no problems whatsoever with the server until now. I played normally yesterday, and suddenly today i keep getting disconnects(The classic: "You have been disconnected from the server" pop-up) on Icecrown(which I main), Lordaeron and Blackrock, but somehow am able to connect only to Frostmourne. I have tried unplugging and replugging the UTP cable, restarting the game, deleting the realmlist and changing it back again. I don't know what to do, I'll try to restart my PC but I doubt it's going to work. If anyone could help me out, i'd be very grateful. Thanks in advance.