Sudden crippling FPS issues after a year of stable 20-30 FPS

Hey guys. I'm playing PoE on my potato-puter, a bootcamped 2011 MacBook Pro with a 2.2 GHz i7 CPU, 8 GB 1333 MHz DDR3 RAM, and an AMD Radeon HD 6750M GPU.

The GPU has been giving me some trouble before, so I've been running with texture quality set to 3, and using the -gc 2 command line option. Both of which have helped immensely ever since I started using those settings, and I haven't had any performance issues for as long as I can remember.

Yesterday though, my FPS went from a solid 30ish to anywhere from 1 to 30, depending on the situation. It just flat-out freezes for a second here and there if there's lots going on, but typically lies between 5-20 when engaging enemies. I tried enabling the --nosound option, which seemed to help a bit, but it's still definitely worse than before.

The client wasn't newly patched. Windows is set to download essential updates automatically, so that may be a thing. My GPU and audio drivers are installed manually though. I went ahead and updated to the latest Catalyst drivers from Guru3D, but to no effect. I also checked to make sure there were no resource-heavy processes running apart from PoE.

Somewhat stumped as to what to try next, any ideas?

It's possible with all the driver updating, some settings got changed, such as v-sync. V-sync would cause the game to run at 30FPS, then 15FPS when it dips, then 7.5 or 1 or whatever when it's really dipping, that looks very choppy compared to no v-sync. Check in the catalyst control center as well as in the game menu for changes.