The recording step was finished, otherwise you could not have quit Audacity. WAV backups at each stage of a complex project are always a good idea.
WAV is a unitary file format. Audacity Projects are a complex format, where an AUP file has entries pointing to large numbers of AU files in a _data folder for the project. The AUP file is written last, after all the AU files have been moved from the Audacity temporary folder to the _data folder for the project.
Unless you have fixed the problem, I suggest you attach the AUP file. We can’t see what the problem is unless you do that.