Really sorry to hear you have had problems saving your project.
When working on a project is is always advised to save to a new file each time. Never overwrite the existing copy unless you have a backup saved. That way if you encounter an issue like running out of free space you will still have a working version saved and available to use.
Sadly if you didn't save to a different file, or kept a backup, then it is unlikely the project can be recovered. If the file is showing 0 bytes then the project is incomplete and won't be able to be reloaded.