Build Mode Freezing

I load the game. I play for 5 mins. I go to Build Mode. After I start building, for example, let's say I'm building stairs and adding a platform, the platform tool does not line up on the grids, now the walls don't line up on the grid and once you drop them they go on the grid. That's when I know when its about to glitch out. Then I can't even delete or place anything. This is all in a matter of 5 minutes of opening the game. I can't save or exit out. It completely freezes. This has been happening for a month now. I have no mods, it does it even without cheats. I've tried repairing it but that doesn't work. Can someone please help?