Null Graphics + Missing Chunks of the map

Loading into the game, getting into the main menu (where you observe single player, community, multiplayer, etc) shows horrid graphics, the squirrel is nowhere to be found, and the ground becomes grey tiles. When I enter a single player, multiplayer, and modded community server, chunks of the map just disappear and I fall into ocean. All observable ground is still grey tiles and others can observe me falling through the ground while everything looks normal on their end. I'm able to go onto a different account and the game is fine, it's as if my account itself is bugged?

Same as description, chunks of the map is missing on both unmodded and modded singleplayer and community server. Graphics are as if they're on their lowest, and then some (they're all on high, and changing the graphics doesn't effect the graphics)

I believe the game would look...normal, if this didn't happen, I'm not entirely sure what this one means