Thanks for reaching out. Sorry to hear that your actions are missing. We're here to help.
Which version of Photoshop are you using? Did you update the application or operating system?
Do you have a backup copy of your actions saved? Please check this article to know how to get Actions when they go missing while you update Photoshop or install Photoshop on a new computer: https://helpx.adobe.com/photoshop/kb/migrate-actions.html.