Super choppy framerate/lag after a while of playing then unexpected error

[Veezora]

Just thought I'd chime in and add that I am also experiencing this exact problem seemingly since Stormblood.

System specifications:
Windows 7 64-bit
Steam version of Final Fantasy XIV: Stormblood
Nvidia GTX760 Ti OEM card running recent drivers (I did try updating them after the first FPS drops but saw no improvement)
16 GB RAM
Using the most recent DirectX compatible with my system

Start game in DX9, game runs as normal for 3-4 hours and begins experiencing massive fps drops and freezing at random intervals, ultimately becoming unplayable in some instances until the game is restarted or crashes, where it will again run 3-4 hours unhindered. I did try switching to DX11, which ran smoothly for a bit, before ultimately ended with an immediate (but temporary) loss of video from my monitor and game crash with no prior warning. As soon as the game begins experiencing the issue, exiting the game always results in a crash displaying this error message:

An unexpected error has occurred. Exiting FINAL FANTASY XIV.

ffxiv.exe+369A36
ffxiv.exe+4FA52
ffxiv.exe+52635
ffxiv.exe+C19EA9
kernel32.dll+1336A
ntdll.dll+39902
ntdll.dll+398D5

Though I haven't experienced teleporting between areas to cause the crash, loading higher resolution models may have something to do with it, for some reason dropping from the top of the Holstrey tower in Kugane to the ground has caused me to crash twice. Oddly, once the trouble starts to manifest, my Steam screenshot function no longer works, though the rest of the overlay does, and attempting to use the screenshot feature integrated in the game also caused a crash.

Hopefully Square Enix addresses this issue, since it seems to be affecting more than just a few people.