i can't connect, help please

A couple of days ago, the game started giving me a problem:
When I try to connect to the server, I get the normal login success messages, but my characters don't load, and the realm selection screen keeps repeating.
I haven't changed anything on my PC, network settings, or firewall.
I'm using the correct realmlist from the download guide on the server's website.
I'm using the wow .exe file to log in.
I haven't re-downloaded the game yet so I don't lose my addon and general game settings.

(I only use PvP addons like Gladius and WeakAuras, since I play on Blackrock).
And according to my account status, I don't have any bans or anything like that: I've never written or done anything to warrant a penalty.

I'd appreciate any help you can give me, as I play occasionally, and I recently managed to find a 2v2 arena partner. Thanks for your help.