....delete the aplication of the facebook.... and go to the game again... if I remember well in some games, and aplications, I started of 0... because I have to give "permision" again to the game to see my facebook profile and all this information that the game needs... really at now I'm not sure, but you can try... or,
what the people say's... at the end every season is the same, only change the nº of level (level1, 2,3,4,5,20..) with the difference that is more easy to win the Champions league when you start... not in the level 10... but all is the same every season, so you can continue without problem writting your history.