Glad to help you. Hope these fixes can work out your problem.
( 1 )If you can see your USB drive in the Disk Utility:
- Launchpad > Others > Disk Utility.
- Select your USB drive, then click the First Aid on the top menu, and click Run.
- Wait for the repair process, and click Done.
( 2 ) If you can't see it in the Disk Utility, check it on another Mac. If nothing happens, maybe there is something wrong with your USB. You'd better use effective software to recover all your data such as iBoysoft Data Recovery for Mac, an Apple-trusted and professional tool.
( 3 )Uninstall CleanMyMac X. Many Mac users say this app may cause corruption, disk problems, or other misbehavior in the macOS. Using Finder or Launchpad just only move the application but there are still some associated files on your Mac, feel free to download iBoysoft MagicMenu to uninstall all data completely of CleanMyMac X with the right-click menu.
Hope you can find all the data and use your Mac as normal.