Yes, and you'll probably need to amend at least your 21 and 22 tax returns, which is unlikely to impact your tax liability anyway.
Whether you continue to have ties to the country of your most recent marriage, does not mean it is irrelevant. It's not about your feelings. The fact may well be quite important. Is it some kind of secret?
My suggestion that it might be best not to list the bigamist marriage, was not to keep THAT a secret, but rather to be entering accurate information, as you know that FACT today. That you were party to a marriage, you later found out was legally invalid, need not be a secret. Just explain. These things happen. You dealt with it as appropriate and necessary. All who need to understand, WILL understand. It's a non-issue, as long as it is dealt with honestly.