Welcome to the forum, @Chumpchops. I hope you haven’t really lost all your files. Even if they no longer appear in the Hub that appears when you start Dorico for iPad, they should still be on your device – as long as you haven’t manually deleted the app from your device.
Take a look in the Files app, and you should find a Dorico folder inside On My iPad, and potentially another Dorico folder inside iCloud Drive. Your projects should be safely in there.