Game Performance Completely Ruined

Waffleflappers

I've only been playing for about two hours now and all of the sudden everything is laggy as if I were playing this game on a 15 year old computer. When I say laggy, I mean like 1 frame of blurred motion every few seconds. Not exactly playable. All I was doing in the game before this happened was swimming around and looking for Table Coral while using the new specimen finding thing. I wasn't performing any other actions beside movement for a good while prior to this. I am playing on a brand new computer that I have owned for less than 24 hours and the game was working perfectly fine beforehand, on max settings. I tried lowering the settings completely, restarting the game, and restarting the computer, but the problem persists. I was at least able to save the game before closing out.

Waffleflappers

One last thing to note, this issue occurs anywhere within the game, even the main menu. And if it wasn't heavily implied enough, I am playing on Steam. Windows 10.