you will have to cut the area out and add new sheet rock. Ceilings are hard to fix. Maybe call a contractor.
This site has a four step fix for your problem.
http://www.doityourself.com/stry/how-to-paint-after-a-ceiling-leak
We seem to have some unwelcome Mickeys and Minnies in our house. What is the best way to get rid of them?
I want to remove my popcorn ceiling, but it has asbestos in it. How do I go about this safely?
How do I fill gaps at baseboard, should I caulk? If so, does anyone know how to caulk baseboards?
How do I fix squeaky hardwood floors?
you will have to cut the area out and add new sheet rock. Ceilings are hard to fix. Maybe call a contractor.
This site has a four step fix for your problem.
http://www.doityourself.com/stry/how-to-paint-after-a-ceiling-leak