Welcome to the Candy Crush Saga Community
Do you have a question or need help with your game? Ask the Community.
Level 1
It's because the app is designed to save the highest level, so if you log in with an account with a lower level, it will automatically overwrite the existing game.
I don't think you can get the boosters back but to seperate the games, I saw these steps in another thread which should help:
-log out of Facebook in the Candy Crush app
-log out of the Facebook app
-Turn off your device for 10 minutes to clear the cache memory.
-Turn it on and Log into Facebook under the required account
-Open Candy Crush and connect to Facebook.