Unable to do any cross-server instances

[Melodia]

Starting from yesterday evening, I'm unable to do any cross-server instances at all. My character would literally be in limbo the moment she enters an instance. She can run, but nothing else works. Enemies are animated but frozen in place. If I use an attack, it literally activates A WHOLE MINUTE later. This is not a lag spike, it's a frickin lag rocket. Most of the time the attack simply won't activate at all. I do NOT get a "you have been disconnected" error until MUCH later (like 30min, though sometimes my client simply CTD without any error), so technically I'm still connected?? What in the world is going on? There's nothing wrong with my connection, because:

 

• I can play rest of game just fine
• Normal ping
• I can access internet just fine

 

Already contacted "support", if it can even be called that. Of course they didn't bother reading the question, and of course they gave the same system-generated all-purpose and completely useless "do a dxdiag" response, which I'm sure is copy/pasted into 50% of all tickets received.