Your situation is a bit complicated in terms of a malpractice suit, as it is not clear if the attorney represented you or just your husband. If the lawyer represented both of you, or wasn't very clear about the potential conflict of interest, that could create a serious ethical problem for the lawyer. Faking information on legal documents also raises significant ethical concerns. Also, malpractice laws vary by state, and you did not indicate where any of this occurred.
You should probably consult a malpractice lawyer in your state about the problems you had with this lawyer. You should also consult a family lawyer about how you can remedy the marriage problem - some laws have corrective statutes which allow people to obtain back-dated or undated marriage certificates.

