copy your database before you do anything. you don't want to make it worse.
hopefully it's not too late, but the important think is
a) split your databases
b) back up your data (backend) every day (or even more often)
c) ensure you have a safe unused copy of the front end, in case the one you actually use gets corrupted.
d) when developing, copy the database versions regularly.
This way the worst you can use is the input since the last backup.