I guess your backup is corrupt, which can happen because of a lot of reasons. e.g. power switching off, faulty SSD/HDD, interrupting a process and so there are a lot more to think about. You probably have to rebuild your library from scratch even though that means losing your current edits.
With all due respect, but if you make that many edits (you indicate you did tons of edits, and it is that drastically that you would leave roon if a fix was not applicable), you should make a regular database backup and not store it on your server. That’s asking for a disaster to happen (think of cloud solutions).
Here is one solution which worked for someone with a 1.8 migration to 2.0. Roon Migration Flub-up - #41 by Bruce_Barbour