If you’ve scammed online, the worst thing you can do is nothing.
According to the Australian Government’s Scam Watch website, last year Australians lost 851 million dollars to scams (that’s just the scams that were actually reported).

If you’ve been impacted by cybercrimes like fraud, identity theft and malicious software you should take immediate action.
The first point of action should be scamwatch.gov.au or cyber.gov.au where you’ll find links for both reporting what’s happened to the relevant authority where you live plus any support you may need following the event.

Again the key message here is to reach out and report any cybercrime activity and get help to ensure it doesn’t happen again.