Hello,
I am sharing my experience so other people don’t lose 2 weeks work too. I’m also looking for help/advice on how to best restore my app.
TIP: Be very careful changing things in the database!
I deleted a relationship in a collection (one to many) and replaced it with a relationship (many to many). I thought this was a logical step. It wasn’t.
This action caused errors through the whole app in the editor and there is no way to roll back the database to a previous version.
I raised a ticket with the day and time of the incident, but there is no way to roll the database back. So be very careful.
I’m still waiting (a week) on advice of how to restore my app from customer service. 
Maybe one of the super Adalo community out there can help in the meantime? 
What is the best way to:
- Change the relationship of a collection without breaking your app
- Restore a database to a previous version, or how to delete collections/relationships safely as not to cause errors?
Many thanks!