All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
The presence (and consent) of the guardian of the bride is one of the conditions for the validity of marriage. If you were a Christian when you got married and the priest married you off to this man by proxy from your guardian or because you had no non-Muslim guardian, while fulfilling the other conditions for the validity of marriage like the presence of the two witnesses and other conditions, then in such a case your marriage was valid and you became a wife of this man.
With regard to the divorce that took place in the court, if your husband did not utter the word divorce or did not write it down on paper while having the intention of divorce, then the divorce that was issued by the court is of no effect because divorce in Islam is in the hand of the husband.
If we suppose that the divorce had taken place, and you are still in the waiting period, then it is permissible for your husband to enter upon you and be in seclusion with you as you still are considered like his wife. Besides, if he wants to take you back during this waiting period, there is no need for a new contract or a new dowry. However, if the waiting period has expired then you are a marriageable woman to him and in this case it is not permissible for him to be in seclusion with you, or talk to you except for a need, like asking about the child and the like.
Finally, it should be noted that it is more appropriate to reconcile if possible and go back to your husband, especially that you have a son from him. So you have to endeavour to this effect. Besides, one should not resort to divorce as a solution to marital problems.
Allaah knows best.