Hi @carolinem16874911, thanks for the reach out. Users have faced similar issues and I understand your fustration. Your files should be there and might only need to be converted to the new version. Have you used the mobile app? You can take a look at -> https://helpx.adobe.com/express/express-faq.html under "I use Adobe Express on desktop and I also use the mobile app. Will my files automatically show up in the new version of Adobe Express?"
Let me know if this helps.
-- Petre