Hi,
Unless you have a backup i think you can not get it back anymore but i am not sure.
but thing you could try for future, make an empty object and place your fsm there and place your object (that you might modify) as a child, another possibility is to make a template of your fsm.
But the best thing to do always make backups, there are several ways to do this (automatically)
for example with github and sourcetree.