Hi there,
We're sorry to hear that your data is lost. We're here to help.
Did you restart the app or re-installed it? Do you sync your works? Are the edited files lost, or is the entire bunch missing? Which version of Lightroom mobile are you using?
If you have re-installed the software, check this article to see a few methods to retrieve them: https://helpx.adobe.com/lightroom-cc/using/lost-photos-presets-lightroom-mobile.html.
Let us know if this helps.
Thanks.
Ranjisha