I had the same problem. Almost had a heart attack..
The Solution (it worked for me)
Make a new project with the same settings as the old one. Go to import, find your old project. Select it and a box will come up asking you whether you want to import the whole project or just selected sequences. Chose selected sequences, then find the sequence you were working on and import it to the new project. You will have your cut, but you may have to re-import some missing video files.