Looks like you created a new account on this email address, instead of changing your account. Your other account is a Plus account with the email kerrie.ocallaghan@rfdsse.org.au if I’m correct. It still holds the project you’re talking about.
You have to delete your kerrie.ocallaghan@gmail.com account in the “my account” tab, and can then change the email address of your plus account, also in “my account” > profile