Fearing being found out as a fraud is read as success outgrowing self-image. The dream points to a gap between what you have done and what you feel you deserve.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.