Since you use Windows 10, an erased Project aia file might be in your Recycle Bin if you originally stored the aia file on your computer.
If you deleted a Project from your online My projects storage, you need a copy of the project (the aia file) that you have regularly been saving to protect against data loss to recover.
If you did this

and pressed OK, then, sorry, your Project is gone forever. The good news is you programmed the app before and you probably can re-produce it and probably even improve it with the skills you have acquired Carlos..
Regards,
Steve