Single Player Game freezes a lot and now after a freeze half my base is gone

Game mode: [Online | Singleplayer]
Problem: [Crash | Bug | Performance | Misc]
Region: [Here]

[Free text]
I play offline so I do not believe the disappearing stuff is caused by online. I have been grudgingly dealing with the freezing up and restarting, but now after having to do it all the new additions to my northern base are gone and the second floor of the portion that I have had the longest is gone now. I don’t know if I can get back on the game if my work is going to just disappear.

Steps on how to reproduce issue:

  1. I don’t want to even think of reproducing the issue…