Can't progress in campaign due to constant crashing

I'm currently in act 9 and the game is constantly crashing to desktop when I click or get close the the door where the Maligaro fight happens right before the depraved trinity. Game freezes then crashes.

When I log back in I'm forced to run all the way back to that point as any portals I set up are getting deleted and do not appear in town when i log back in. The portal appears on the minimap when I run back to the point where I set it but isn't actually there.

As with many others here, this game was running fine for me three leagues ago, borderline unplayable two leagues ago and I had to skip last league entirely because I couldn't get out of act one without massive load times and constant crashing.

I absolutely love this game but its become beyond frustrating to play.