Weird Performance Issues

Dear Mojang,

Recently, when I was playing Minecraft 1.14.2, I was setting up a server for me and a friend. When I created the server I logged in to it, and the server was really lagging for a couple of seconds until the game started to reach 60FPS. When I exited multiplayer and went in to singleplayer mode to load up one of my worlds, the game's FPS was very choppy, and the memory allocation was at 100%! I was surprised, and I was wondering what is wrong with Minecraft. It also happened last night too. This morning, when I was playing the game again, Minecraft was dropping to 40-26FPS, and my laptop is plugged in to keep it at a smooth FPS. When I played Minecraft 1.14, the FPS was fine at 12 chunks with the screen resolution at my monitor's maximum which is 1920x1080 60Hz. Now, my game is lagging a lot. Now, when I play Minecraft, I noticed that there are lag spikes with dark green forests that have big mushrooms in it. It happens when I break or place something. I would appreciate it if you guys can fix this issue. Thank you and have a blessed day!

Sincerely,
Joshua Ottey

P.S. The drivers for my NVIDIA GPU are up-to-date, and I reinstalled Minecraft entirely with also deleting the .minecraft folder.