Upvote:4
Based on a google book search, I believe this quote comes from:
It appears to be available on Amazon, and I also found a very poor transcription on archive.org.
The quote in the book is:
Expressed in another way, sin is living the lie of believing oneself to be self-created, self-sustained, self-dependent.
It's not exactly the same as the quote you find out there, but its pretty close, so what likely happened is the quote got mis-attributed to Augustine when it was actually a summary of his teaching.