Hello, i was doing som landscaping as final touch up of my scene. I decided to undo a lot of actions, by pressing ctrl+ z. And UE4 crashed on me… no everytime i try to load my project it crashes. Please somebody help me recover my work, its due soon 
If you don’t have a backup then I suggest you start rebuilding it now. Undo has corrupted many a project. The only thing you can do is revert to a backup.
Feel free to post the log with the error(s) in it, but I’ve never seen anyone recover from this kind of issue.
Best practice is to backup more often than you’d prefer and never save before compiling so bad changes will get lost. Sorry I can’t give you better assistance. If it helps: we’ve all learned about Undo the hard way so you’re not alone. In fact I have a post about it here.