Lag/stuttering while mouse looking has gotten unbearable

[LiQuid]

In dense zones or where there's a lot of people when I mouse move my camera this game basically goes into single digit FPS mode and I can't figure out why.

Here's a fraps I took that shows it off best. Watch after I get feared here when I'm trying to spin back towards the mob:

https://youtu.be/ivMyD-JE_2c?t=25m1s

There have been a few threads on this in the past that I've found and I've tried every possible solution listed in them from capping at 60 FPS, making sure video drivers are current, all the way to installing a fresh version of client to play off of, and nothing works. I've tried running the game with and without WinEQ2 and I've tried messing with all of the options in there. I've tried seeing eqgame.exe's CPU priority higher. I'm at a loss for anything new I can even try.

I don't remember the game always being like this. Back when I played in 2012-13 I played on a reeeeeally bad, old Dell laptop and it ran totally fine. When I first got this PC in 2013 and continued playing for a while it ran totally fine. Then when I came back to the server about 6 months ago it ran totally fine. It's just been in the last few months that it does this.

Any suggestions appreciated.