A Microsoft file hosting and synchronization service.
Hi, and welcome to the Microsoft Community.
By default, the local OneDrive folder does not contain a copy of your computer's files. It is where your original files reside when the PC Folder Backup is enabled in the Manage Backup settings.
I suggest you check the recycle bin at onedrive.com and the PC's recycle bin for your deleted files. The remainder of your files need to be recovered from your hard drive. I suggest file recovery software or a professional file recovery service.
For the best account support, you should Email the OneDrive support team.
Sorry, I don't have better news.
Craig