Who can help to restore my career?...
The child overwrote a name in my career...
more than 50 % were at that time passable.
...whether it is possible to restore career?
Shouldn't be possible unless you're playing on PC and it didn't synchronize with Steam yet if you've Steam Cloud enabled. Same goes for PS3 + PS3 Plus cloud savegames.
Learn from this even more, and don't let your kid near your PC/console
My 4 year old nephew can do all kinds of havock once he gets his hands on my keyboard...