[2022] Iron man save is broken

The save file will be half updated and half old, which is to say irredeemably corrupted. There is no possible way to fix that, I am sorry.

In future I'd suggest you manually make a copy of your Ironman saves, either just before or just after each play session.  

How do you copy a file in Windows, are you asking?

Right click on it in File Explorer, copy. Go to a different folder, right click in there, paste.