it appears that your husband first wife filed for divorce and your husband never contested the proceedings . if your husband di not attend divorce would have been granted by court exparte . once divorce has been granted his subsequent marriage to you was valid .
among Christians marriage is a covenant.In marriage, the covenant is between a man and a woman. The spouses establish this covenant through their marital consent, by which they intend to establish between themselves a partnership for the whole of life. This means each spouse will assist and support the other in all areas of their common life, the best he or she is able, so long as the other spouse is alive.
A Catholic annulment, also known as a declaration of nullity or invalidity, is a statement of fact by the Catholic Church. After carefully examining the couple's broken relationship, the Church states that a valid marriage, as the Church defines marriage, never existed.
if no annulment has taken place you cannot remarry in church . if your marriage has taken place in church without annulment in eyes of church your husband is still married to his first wife .
in your case it appears before your marriage in church your husband had sent letter from his church to your church . what were the contents of letter . it is better to contact a local lawyer before proceeding further for divorce