My brother and sister-in-law went through a similar situation. After the majority of her pregnancy, in the 7th month, she went to the doctor on a normal visit. There was a problem. Not enough fluid in the amniotic sack surrounding the baby. There were three prognosis; 1) Faith would die in the womb, 2) Faith would die shortly after birth, or 3) Faith would live but be severely handicap her entire life. The doctors offered the option of abortion. My brother, a deacon in the church at the time, and my sister-in-law refused to even consider this option. I was in the delivery room during the birth and was blessed with spending 9 minutes with my beautiful niece before the Lord called her home.
My brother and sister-in-law never recovered. They both have fallen far from their relationship with the Lord. To be honest it even tested my own faith. Although this is a terrible tragedy to happen to you and your family, do not let satin have the glory in this situation. My brother and his family, to this day, have not returned to church. Philippians 4:4 "Rejoice in the Lord ALWAYS, and again I say rejoice."
When times are tough and the circumstances seem to be overbearing, just remember that all things work for the glory of God. Pray, pray, then pray some more. I agree with you that "having another child" will fix the tremendous sorrow you feel, it will not. But rest assured that our Father has a perfect plan for you and that He will heal your pain. I will be praying for you and your family. God Bless