So Katie - who was given sole custody of the couple's six-year-old daughter, Suri, in the divorce settlement - has sought professional help in a bid to move on.
A source told Britain's Grazia magazine: "Finally free from Tom, Katie is keen to find her own voice. So she has sought professional help and has employed a confidence coach who she's been seeing once a week to help her regain who she once was."
Although Katie has no regrets about the split, insiders say she is struggling to sleep because she has a lot on her mind at the moment.
The source added: "The glow and radiance that defined Katie post-split seem to have evaporated. She won't have anticipated that she would suffer from a complete lack of self-confidence, and what it would actually feel like not being Mrs. Tom Cruise. It's like she's struggling to regain her own identity while balancing work, motherhood and keeping Suri grounded. With so much on her mind, it's hardly surprising that she's not sleeping for more than five hours a night. She doesn't regret what she did - far from it. But she's found it harder to carry as normal these past few weeks."