If you had witnesses present during your consultation with the attorney, then the attorney-client privilege may have been waived. You should have objected to that attorney representing your husband long before now. It is likely that you will be deemed to have waived any conflict. It is not likely you will prevail now, but you should consult with an attorney in person and not ask from us what we cannot give you, which is the odds of your succeeding in a motion to vacate unless you were not present at the custody hearing due to default. There just is not enough information exchanged in this forum to answer your question. Please see an attorney in person for more help.
You have likely waited too long to now object to this likely conflict of interest. However, bring the facts to a family law attorney and discuss your prospects. Good luck
So far, this is free to you. Until you pay a fee, I am not your lawyer and you are not my client, so you take any free advice at your sole risk. I am licensed in IL, MO, TX and am a Reg. Pat. Atty. so advice in any other jurisdiction is general advice and should be confirmed with an attorney licensed in that jurisdiction.