[Major Performance Issue: Frequent Periodic Freezing]

I recently started Pillars up again for the first time in a while and discovered it's basically impossible to play. I'm experiencing freezing every two or three seconds in-game (no FPS drop), and CPU usage is quite high even with no other processes. I find this very strange as the game was running perfectly before.

 

I had a similar problem with Overwatch but it fixed itself once I enabled full screen.  Tried fullscreen with Pillars but to no avail.

 

Is anyone else experiencing something similar? Please help!

System Specs:

Windows 10 Pro 64-bit Processor: Intel® Core i5-3570K CPU @ 3.40GHz (4 CPUs), ~3.8GHz 16 GB ram Radeon RX 480 Graphics 8 GB

[DONATIONS CLOSED - Brace yourselves, the Black isle Bastards are coming!]

How about some sort of a mini hand-held cannon for a weapon?  I was thinking maybe something like the rat boss in Grimrock 2.