We need to accept that we won't always make the right decisions, that we'll screw up royally sometimes - understanding that failure is not the opposite of success, it's part of success.
The fastest way to break the cycle of perfectionism and become a fearless mother is to give up the idea of doing it perfectly - indeed to embrace uncertainty and imperfection.
I think while all mothers deal with feelings of guilt, working mothers are plagued by guilt on steroids!
Trying to be Supermom is as futile as trying to be Perfect Mom. Not going to happen.