Hey, this just happened.
Logged in and got instantly disconnected leaving me on the Character selection screen.
Tried logging in few times and it worked after like 5-6th login.

Is that my problem or account/server side?

Hi there Akaforty,

We have had a good many similar reports since the most recent Patch, so there is a strong likelihood that the issues you mention will stem from any changes made to the game (and the resulting outdated cache files or addons that can occur as a consequence).

If you do continue to experience this problem, then I would firstly advise you to take a look at our current sticky post regarding various types of login issues following the Patch;

27/03 Login Issues
30/03 Login Issues

If necessary, you may also need to try repairing your game client using the WoW Repair Tool.exe, which you should be able to find located within your World of Warcraft directory. The second half of the following post (also linked to in the above sticky) should hopefully explain how to go about the repair process;

Reset UI - WTF, Cache, and Interface folders
Frequent Questions and Answers

I do hope this helps solve the issues. :)