Lost all linux VM changes from 8/16 - 8/22. Possible to get those changes back & What can I do in the future to avoid this?

Hi, 

I'm having a serious concern with the VM, as the title says I lost all of my change from 8/16 to 8/22. This was noticed on the 23rd, I am wondering if due to maintenance all changes were reverted back to 8/16? I need to know if its possible to get the VM back to state it was at the end of the day 8/22. 

More importantly - I need to know how to avoid such regressions of the VM in the future.