My sincerest sympathy for your loss.
I suspect that anybody who has worked with any kind of CAD, CAE or EDA tool for more than 6 months has experienced something similar. The most practical solution to the problem is "backups" or "archives". I have trained myself to create fall-back copies at least twice a day when I'm actively engaged with a project. The automatic backup feature in many programs is of limited help, unless it lets you retain those backups at least 3 or 4 deep.
(Consider: You set the automatic backup to operate, say, every 15 minutes. After you do something stupid, you typically spend the first 10 minutes just verifying that you did something stupid. Then you spend 10 minutes trying to un-do your stupidity. Then you spend 10 minutes trying to calm down, cover up, and deny your stupidity. By this time, the automatic backup feature has preserved your stupidity twice over.)
In exchange for a serving of my preferred malt beverage, you can be assured that neither your co-workers nor your supervisor will learn of your mistake from me.