My score has been deleted

This ain't the place to post, mate. A better place to put this would be somewhere in general discussions.

MuseScore never ever deletes your scores. if you deleted your score yourself, try the trash bin. If you simply can't remember what folder you saved it to, try Finder. If you continue to have trouble, please ask for help in the Support forum - as mentioned, this forum is for official announcements only. If/when you do post to the Support forum, be sure to give more info to allow other to understand and assist better - what has led you to believe the file is deleted, the exact pathname of the folder you believed you saved it to, etc, what you see when you list the contents of that folder, what else you' have done in your attempt to find the file, etc.

May I kindly ask the mods of this forum to somehow restrict general posting in the Announcements forum? I personally subscribe to it via RSS to get updates on MuseScore since this is a great place for that, but obviously non-announcement threads will also show up in the RSS feed and it makes it a bit more confusing to navigate.

To the OP, on macOS, your best bet would be having something like Time Machine setup to help aid in such situations. Likely you deleted it by accident or similar. I'm not aware of any other way to recover files without a backup on macOS.