Is it permissible to supplicate against my husband who divorced me after I gave birth to our child, knowing that he wronged me and threatened to take the newborn, and will I be recompensed with the like of what I supplicated for?

It is not permissible for a husband to wrong or insult his wife. This might be a trial from Allah. It is recommended to observe patience, prayer, and seek assistance through them. It is permissible for the wronged person to supplicate against the one who wronged him, for the supplication of the wronged is answered. As for the custody of the child, the mother has the primary right to it, unless she remarries or the child reaches the age of choice.