Someone changed my email address

My gmail address has been changed (not by me). I went through all of the steps in the help center documents to see if I've been hacked. My account doesn't show any devices or security events that aren't mine. When I log into my old address, it logs in as usual, but takes me to the new account. This is not an additional account that has been added. My user setting is only showing one account. I seem to have full access to this account and it seems to be continuing to function as if nothing was changed. All of my old emails are in this account. I still get emails directed to both the new and old email addresses. I looked through all of the “someone changed my email address” threads in the Community section and the answers I found was to “try recovering my username,” and to delete the false account. I followed the link to recover my user name, but it took me right back to the same changed email address. I can’t delete the false account because there’s only the one account and if I log into my original account, it takes me back to the new one. Did google change my account and if not, what should I do?