Performance issues since 0.28

I have been having awful performance issues on PC since the 0.28 patch. Specs are:

i7 8700k
32GB DDR4 RAM
1080TI GPU
Playing at 1080p

Before the patch, my game was fine, and I'd hit a solid 120fps practically everywhere in the game, with very, very few frame drops. Hours of play at a time without any issues aside from very minor hiccups every now and again.

Now, it will be fine for about 20-30 minutes, then I start getting unplayable stuttering. It starts off slow, and just continually gets worse. It eventually gets to the point that the game is a slideshow. I've attached a photo of my current performance during one of these periods where its really, really bad. Why is the game using nearly 90% CPU, and 45% GPU? I don't know what this was before the patch, because I didn't have to check, but that's pretty wack.

My specs are old, for sure, but having such a huge degradation in performance between patches doesn't point to much except something coming in with the most recent patch. Be it poor optimization with the new lighting/balloons and **bleep**, introducing a memory leak, or just something else that has made the game become far more CPU bound.

I can play fine on my xbox, but I really preferred playing on PC, because its easier to play with friends and use discord and such. I asked around on discord, as well, and it seems to be happening to a lot of people, on both PC and Console. So, hopefully a fix comes sooner rather than later, unlike it did with my progression softlock that took 20+ days to fix.