Low FPS

When I was playing my world, it became laggy, and I noticed how if I looked in a certain direction, my frames would slow down and lag. I then ran a few small tests on Malwarbytes, but nothing showed up, so I opened a debug screen in Minecraft by typing alt, fn, and f3 at the same time. When i looked in the same laggy direction of my Minecraft world, the frames dropped dramatically and it again became laggy and even nauseating to see.