Practical advice for everybody reading rather than for your current problem: write in something that keeps version history and leave it on. An essay that grew over four days with deletions and rewrites looks nothing like one that appeared in a single paste, and that record is the only defence that does not depend on anybody believing you.
Invented sources are the other half. A citation that does not exist is usually how a suspicion turns into a finding, and it is worth checking your own references for that reason alone.