Massive lag client-side

My internet works fine for everything (including the Warmane website) except for WoW. Yesterday I had 200-300 ms (my normal latency) in populated cities like Dalaran or Orgrimmar, but today it reached a peak of 25k ms. It's unplayable and there doesn't seem to be anything malfunctioning with my internet.
I don't know what may cause this, but I heard some people had the same problem, except it 'fixed itself within 10 minutes'. In my case it's been like this all day, and messages or interactions can delay up to 5+ minutes in the worst cases
Thanks in advance

Im having the same problem, trying to play on frostwolf
I reseted my router twice already, but everything else is working flawless on the same internet connection, the moment I step ingame it gives me from 2600-11k ms
Did internet connection tests and its all as it is supposed to be, I played yesterday without problems
I am from Brazil

I have the same problem. Yesterday i was playing with 230-300ms (the normal for me) and today like 15-20k ms. Nothing seems wrong with my connection please help thanks

It's impossible to play with this lag. It gets better when I'm in unpopulated areas, but I can't do anything when in cities. Was able to open an in-game ticket, and the GM's answer was to delete Cache and WTF folders. I had already done it -although I tried again, just in case- and it didn't work. I can't seem to find any solution and it isn't my internet's problem.