I FIGURED IT OUT!
After a bit of searching I saw a lot of people saying that adding an exclusion for Project Zombiod in their anti-virus fixed it for them.
I tried adding Project Zomboid's steam folder to the exclusion list but the freezing persisted.
That's because you also have to add an exception for Project Zomboid's user folder as well to fix it. (C:\Users\YOURNAME\Zomboid)
After that the freezing disappeared and I restarted the game a few times to make sure.
My best guess is that the anti-virus is trying to scan the user files and saves in real time but the game is also trying to modify and update the files every 10 in-game minutes which causes some sort of conflict or performance drop.
My anti-virus is Bit Defender for anyone curious. I'm not sure if the problem is unique to that specific anti-virus or not.
