Sorry this happened. Inside, you don't just want to scrape and paint. Rather, you will want to remove as much of the peeling paint as possible. Then skim coat with joint compound, finish, prime, and repaint. Keep in mind that any paint that continues to peel will also bring up your skim coat with it. Better yet, you could just cover all your ceiling with new drywall installed and then tape and finish - for just the ceiling alone that would work and give you a new surface that can be prepped right.
Just a thought - you don't have moisture above your ceiling possibly causing this?